Frame design for reduced-size vehicle

ABSTRACT

Various embodiments of reduced-size vehicles such as all-terrain vehicles (ATVs) and utility vehicles (UVs) are disclosed herein. In at least some embodiments, the vehicles include frames that are wider near the front and rear sections of the vehicles than within the mid-sections of the vehicles. This, in combination with the use of shock-absorbers that are substantially vertically oriented, allows for the opening-up of large interior cavities within the front and rear sections of the vehicles within which can be positioned large front and rear internal compartments that can provide storage/carrying capacity as well as added buoyancy for the vehicle, among other things. Also, in at least some embodiments, the vehicles can include special cooling and/or exhaust systems having components that are positioned substantially within the mid-sections of the vehicles, thus further increasing the amounts of space available for the cavities/compartments within the front and rear sections of the vehicles.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application claims the benefit of U.S. provisional patentapplication No. 60/640,410 entitled “Improved Reduced-Size Vehicle” andfiled on Dec. 30, 2004, which is hereby incorporated by referenceherein.

STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT FIELD OFTHE INVENTION

This invention relates to reduced-size vehicles, particularlyall-terrain vehicles (“ATVs”) and various utility vehicles (“UVs”).

BACKGROUND OF THE INVENTION

Reduced-size vehicles such as ATVs and UVs are becoming increasinglypopular in North America and the world. Historically, ATVs can tracetheir origins to motorcycles. The ATV began as a motorcycle with tworear wheels, called an All-Terrain Cycle (ATC) and then, due to safetyconsiderations, evolved to include a second front wheel so as to becomethe conventional four-wheeled ATV. As ATVs have further evolved over thepast twenty years, many other aspects of the vehicles have also beenimproved. Many of the improvements have concerned the drivingperformance of the ATVs (both in terms of operation of the vehicles in astraight line and over rough terrain). For example, ATVs have becomeequipped with larger and more powerful engines, sophisticated automatictransmissions, and advanced differential technology. The suspensionsystems, likewise, have matured from rigid mounted wheels and tires tolong-travel, fully independent suspension systems.

Conventional reduced-size vehicles offered by a variety of manufacturersshare a number of features in common with one another. Becausereduced-size vehicles (and particularly ATVs) originated as offshoots ofmotorcycle technology, such vehicles in particular share certainfeatures that are similar to those of motorcycles. In particular, aconventional ATV typically employs an internal structural frame formedby a group of struts, tubes, castings, and/or stampings (and/or otherelements) that extend substantially parallel to one another from nearthe front of the vehicle to near the rear of the vehicle, generally inclose proximity to a central longitudinal axis of the vehicle. Thearrangement of struts is such that the overall frame would conform to(e.g., would fit within) the physical confines of motorcycles havinglong, narrow bodies, even though reduced-size vehicles such as ATVs andUVs typically have bodies that are substantially wider than those ofmotorcycles. Although through the years there has been a focus onreducing the cost of the frame, there have been few major innovations inframe design beyond the standard motorcycle design. The frame is seen asthe structure that carries the critical vehicle systems but deliverslittle if any additional value to the end user.

In addition to having motorcycle-type frames, conventional reduced-sizevehicles also have other features that reflect their evolution frommotorcycles, for example, in terms of their cooling systems and exhaustsystems. With respect to their cooling systems, conventionalreduced-size vehicles typically employ engine cooling systems in whichair flow moves horizontally along the vehicles as the vehicles moveforward. More specifically, such engine cooling systems (which caninclude, for example, radiators or heat exchangers), are typicallypositioned within front or rear sections of the vehicles relative to themid-sections of the vehicles in which operators are seated duringoperation. When placed in the front section of a vehicle, as is morecommonly the case, cooling air enters at the very front end of thevehicle and typically is then exhausted into the mid-section/operatorspace. When placed generally in the rear section behind the mid-section,as is less commonly the case, cooling air enters from themid-section/operator space and then passes out the vehicle's rear end.

As for the exhaust systems of reduced-size vehicles, the traditionalmotorcycle-based design and packaging of an ATV exhaust system placesthe muffler (which is generally round and cylindrical) at the rear ofthe vehicle, typically in a generally horizontal manner, with the outletnear or at the rear of the vehicle, facing aft or downward. Certainfactors influence the exact positioning of the exhaust systemconfiguration and muffler. First, the exhaust system should beconfigured to function within the confined area that an ATV allows afterplacement of the engine, cooling system, transmission, drivetrain,intake system, and other critical systems. Second, because ATVs areoften operated in water, it is desirable to locate the outlet of themuffler as high as possible so as to minimize water intrusion. Third,the muffler should have sufficient volume to allow for adequateperformance while maintaining satisfactory sound dampening qualities.Fourth, the exhaust outlet should be positioned so that the exhaust airis not discharged directly onto a person who is working in closeproximity to the vehicle. Lastly, the exhaust system should be as smallas possible, so as to minimize radiated heat, and should beheat-shielded and placed sufficiently far away from any operator (e.g.,laced under a rear fender).

As reduced-size vehicles have grown in their size, power andcapabilities, it has been recognized that the vehicles are suitable forperforming a variety of chores and tasks for which ordinary cars,trucks, and tractors are not well suited. To facilitate the performingof these functions by reduced-size vehicles, it has further becomedesirable to create dedicated carrying/storage features on thereduced-size vehicles. Yet, because the primary consideration indesigning reduced-size vehicles traditionally has been to enhance thevehicles' driving performance, the interiors of reduced-size vehicles(e.g., the volumes defined by the outer perimeters of the vehicles) havebeen completely or nearly completely filled with the various engine,powertrain, suspension, cooling and other system components allowing foroptimal performance of the vehicles. To the extent that certain spaceswithin the vehicle interiors have been reserved for storage purposes,such spaces have typically been very small, e.g., with a volume of onlyabout 3 gallons or less. As a result, such spaces typically aresufficient only for transporting small items such as a pair of gloves, atow strap, or an emergency tool kit. Further, these spaces often areinconvenient to use, for example, because the ports/doors are located atlow or otherwise difficult-to-access locations (e.g., under the seat),or because the doors are at low levels and lack seals to prevent theentry of water into the spaces.

Although at least one manufacturer, Bombardier, has integrated asomewhat larger, 8 gallon storage compartment into the front end of atleast one of its ATV models (e.g., the 1999 Traxter ATV), this storagecompartment is still limited in size due to the frame of the ATV and dueto the positioning of the front shock absorbers of the vehicle, andthere is no comparable storage compartment in the rear of the ATV due tothe movement of certain components from the front end of the vehicle tothe rear end of the vehicle to provide sufficient space for the frontstorage compartment. Also, although at least one other manufacturer,Arctic Cat, has integrated a somewhat larger, 8-10 gallon storagecompartment into the rear end of at least one of its ATV models, thisstorage compartment is still limited in size due to the configuration ofthe vehicle frame and the positioning of the rear shock absorbers, aswell as difficult to access insofar as it only occupies a region that isbelow the cargo rack accessible from behind the vehicle. Further, thestorage compartment is located substantially above the locations atwhich the shock absorbers are coupled to the frame of the vehicle, andloading of that compartment with items/materials can raise the vehicle'scenter of gravity.

Given the lack of large internal carrying/storage spaces withinconventional ATVs, ATV manufacturers have developed alternative featuresto enhance the ability of ATVs to carry and move items and material. Inparticular, ATV manufacturers have added cargo racks to the tops of thefenders, first at the rear sections of the vehicles and subsequently atthe front sections of the vehicles. Depending upon the embodiment, arack can be located on top of the bodywork of a vehicle, or in the caseof a carrying bed, on top of the rear tires of a vehicle. The inclusionof such cargo racks on ATVs is now the industry standard. Additionally,although items can be strapped/tied directly to such cargo racks, tofurther enhance the cargo capacity of ATVs, it also has become common topurchase aftermarket storage containers that fasten to the tops of thecargo racks. Also, various enhancements have been developed forfacilitating the coupling of items to cargo racks, for example, ArticCat's “Speed Rack” and Polaris' “Speed Lock.” The use of such containersin combination with the cargo racks makes it possible to carryitems/materials within enclosed compartments such that thoseitems/materials are not exposed directly to the outside environment.

Although reduced-size vehicles with the above-described cargo rack andsupplemental container features continue to increase in popularity, suchconventional vehicles nevertheless have several limitations. First, theattachment of items/materials to the cargo racks is often challengingdue to the need for additional ropes or cords or special clips to fastenthe items. Second, in circumstances where containers are used, orotherwise large items are attached to the cargo racks, visibility can bereduced for the operators of the vehicles. Third, cargo carried on topof the racks can overload the vehicles and/or negatively impact thevehicles' centers of gravity, which in turn can impact the performanceand safety of the vehicles. Indeed, this aspect is of particularsignificance to reduced-size vehicles in comparison with many otherlarger vehicles, both because reduced-size vehicles tend to berelatively light in terms of their weight, and also because reduced-sizevehicles naturally tend to have a high center of gravity for otherreasons—for example, because the vehicles typically are designed to havelarge amounts of ground clearance to clear obstacles while operatingoff-road, and because in such vehicles (particularly ATVs) the operatoris seated upon the vehicle rather than within the vehicle. Consequently,the cargo racks/containers on reduced-size vehicles should be carefullyloaded so as not to exceed the weight ratings of the vehicles.

Another limitation of conventional reduced-size vehicles is that thevehicles have little or no provision for floatation. ATVs in particularare frequently operated under conditions in which the vehicles need toford bodies of water. During fording maneuvers, the depth of the wateris not always known (e.g., if operating in an unfamiliar area).Consequently, it is not uncommon for an ATV to become submersedcompletely and ingest water into its engine and cease running, which isa significant inconvenience for the operator and can cause extensivedamage to the engine. To prevent the above-described scenario, an ATVdesirably would include sufficient displacement integrated into thevehicle to allow for vehicle floatation. Yet integrating sufficientdisplacement into an ATV for this purpose is difficult given thesignificant amount of displacement that is required. For example,typical ATVs weigh approximately 600 to 750 lbs without a rider,unladen. When a rider is positioned onto such an ATV, the ATV canapproach as much as 950 lbs (e.g., supposing a 200 lb operator). Notingthat the density of water is 8.34 lb/gal, an ATV needs to displace atleast about 72 to 90 gallons of water to achieve buoyancy for thevehicle alone and potentially as much as about 114 gallons to obtainneutral buoyancy when laden with an operator (again supposing a 200 lboperator).

Conventional ATVs do include certain components that provide somebuoyancy for the vehicles. Not only does the fuel tank in an ATV providesome buoyancy, but also virtually all ATVs employ the use of “highfloatation oversize balloon tires” to provide buoyancy and, in somecases, pontoons or inflatable inner tubes can also be attached to thevehicles to provide additional buoyancy. None of these satisfactorilysolves the buoyancy problem, however. The fuel tank only provides alimited amount of buoyancy, and the buoyancy that it provides variesdepending upon how much it is filled with fuel. With respect toattaching pontoons/inner tubes to the ATVs, the use of such devices isundesirable for a variety of reasons including complications arisingfrom the mounting/installation of those devices, negative effects onvehicle maneuverability when such devices are installed, and storage ofthe devices when not being used. As for the use of balloon tires, suchtires on average only displace about 12 gallons of water each. Further,as the performance of ATVs is improved, there will continue to be anincreased need for braking area, which will tend to drive up wheel sizeand reduce the available volume for the tires, which in turn willdecrease the tires' overall contribution to buoyancy.

Even if one assumes that a typical ATV has four balloon tires, eachdisplacing 12 gallons, and a typical fuel tank of 4 gallons (and nopontoons/inner tubes), and additionally that the remainingcomponentry/structure of a conventional ATV displaces an additional 20gallons, such ATV will displace by way of these components only about 72gallons of water or 600 pounds. Thus, noting the difference between thedisplaced weight of water and the typical weight of a conventional ATV,and given the density of water, a conventional ATV unladen (e.g.,without any operator/passenger or additional carried weight) at best isbarely buoyant and potentially falls short of neutral buoyancy by nearly20 gallons. Further, with an operator on board, much less any additionalweight, conventional ATVs will sink.

In addition to the aforementioned limitations relating to storagecapacity and buoyancy, conventional reduced-size vehicles also areinadequate in terms of the manner in which the vehicles respond toaccidents/impacts. More particularly, while the frames of conventionalreduced-size vehicles are satisfactorily designed for the purpose ofcarrying the operator and the various internal vehicle systems, suchconventional frames have not been designed with the aim of effectivelydissipating energy if the vehicles hit immovable objects such as trees,or with the aim of reducing the effects of side impacts upon thevehicles. Further, because the struts/tubes, castings and stampingsforming the frames of conventional reduced-size vehicles extend from thefront ends to the rear ends of the vehicles in proximity to the centrallongitudinal axes of the vehicles, the frames are exposed to, and notparticularly well-suited to resisting, extreme forces and torques thatcan be applied to the vehicles in certain accidents where the front endsof the vehicles tend to be twisted in directions contrary to those ofthe rear ends of the vehicles. In general, conventional frames have notbeen designed in a manner intended to enhance the crashworthiness of thereduced-size vehicles.

Further, the cooling systems of conventional reduced-size vehicles alsohave a number of drawbacks. With respect to conventional front-mountedcooling systems, for example, such systems are typically vulnerable toclogging in the off-road environment due to contact with mud, leaves,grass, snow, seeds, etc., and to the possibility of puncture from rocks& sticks. To the extent that extra guards are utilized to preventpuncture, these can exacerbate clogging events. Further, in suchsystems, the radiators exhaust heat into the mid-sections of thevehicles, which can undesirably heat up the seats and the surroundingbodywork and in some circumstances expose the vehicle operators(particularly the operators' legs) to undesirable heat. Additionally,when one such vehicle closely follows behind another such vehicle, thefollowing vehicle can undesirably ingest dirty air expelled by theleading vehicle. As for conventional rear-mounted cooling systems, suchsystems are typically vulnerable to puncture and physical harm when thevehicles are driven in reverse. Such systems also can constrainsuspension design and decrease vehicle system flexibility. To guaranteesufficient air flow, such systems often require large amounts of spacewithin the vehicles to be dedicated to the communication of air forcooling and long coolant lines from the engine to the heat exchanger.Further, in contrast to the conventional front-mounted cooling systems,the rear-mounted cooling systems require fans to force air into theradiator, and hot air can “chimney” back to the operator if the coolingfan is not running.

The exhaust systems of conventional reduced-size vehicles also haveseveral drawbacks. First, the horizontal placement of a muffler in sucha vehicle, in conjunction with the positioning of the muffler above thepower cylinder(s) of the engine of the vehicle, allows water that hasentered the muffler to drain directly into the engine (a condition thatcan regularly occur when operating the ATV in deep water and mud).Second, the horizontal placement of the muffler maximizes the surfacearea by which heat is convectively transferred away from the muffler andonto the plastic fender that is commonly located above it, which canresult in significant and possibly undesirable heating of the fender.Although some reduced-size vehicles include heat shields above theirmufflers and/or highly reflective foil insulators on the bottom sides ofthe plastic fenders, the fenders and surrounding body work of suchvehicles often still can become undesirably hot. Further, even to theextent that the heating of the fenders and bodywork of such vehicles isreduced, the header pipes connecting the engines of the vehicles totheir mufflers typically are run high in the vehicles, just below theedges of the operator seats and horizontally along the vehicles, e.g.,proximate where operators' legs are situated during vehicle operation.

In view of the above discussion, it therefore would be advantageous ifnew reduced-size vehicles could be designed that overcame one or more ofthe aforementioned limitations. In particular, it would be advantageousif a new reduced-size vehicle was developed that could have one or morelarge interior storage compartment(s) for carrying items/material, wherethose interior storage compartment(s) were easy to use and/or werepositioned substantially below the top of the vehicle such thatitems/material contained within those compartments did not overly raisethe center of gravity of the vehicle or reduce operator visibility.Further, it would be advantageous if such a new reduced-size vehicleincluded features that improved the buoyancy of the vehicle.Additionally, it would be advantageous if such a new reduced sizevehicle included an improved frame design to improve the vehicle'sbehavior under at least some accident conditions. Further, it would beadvantageous if such a new reduced-size vehicle included an improvedcooling system arrangement and/or improved exhaust system arrangement toalleviate one or more of the above-discussed problems associated withconventional reduced-size vehicles.

SUMMARY OF THE INVENTION

The present inventors have recognized that conventional reduced-sizevehicles can be modified and improved in a variety of ways so as toaddress one or more of the above-discussed drawbacks of conventionalreduced-size vehicles. In particular, the present inventors haverecognized that, by modifying the internal frames of such vehicles sothat the struts/tubes, castings, and stampings of the frames are notoverly concentrated along the central longitudinal axes of the vehicles,it can become possible in at least some embodiments for largeunobstructed interior cavities to be created within the vehicles attheir front and rear ends, allowing for large interior storagecompartments to be provided within the vehicles. The inventors havefurther recognized that in at least some embodiments the creation ofsuch interior cavities/storage compartments can be further facilitatedby utilizing shock absorbers that are vertically-oriented (as viewedfrom both front elevation and side elevation views) rather thanobliquely-oriented as they extend between the frame and thewheels/axles. The inventors have additionally recognized that, in atleast some embodiments, the filling of such interior storagecompartments with items/materials will tend not to raise the vehicles'centers of gravity (and rather will tend to lower it), and/or that suchstorage compartments in certain embodiments can greatly facilitatevehicle buoyancy. Additionally, the inventors have recognized that theuse of such modified internal frames can in at least some embodimentsimprove the manner in which the vehicles perform during accidents and/orrespond to impacts.

Further, the present inventors have recognized that the cooling andexhaust systems of conventional reduced-size vehicles can be modified toimprove the vehicles' design and performance. In particular, the presentinventors have recognized that, in at least some embodiments, theplacement of cooling and/or exhaust system components primarily withinthe mid-sections of the vehicles rather than in the front or rearsections of the vehicles not only is possible but also can beadvantageous for several reasons. For example, the placement of coolingand/or exhaust system components within the mid-section of a vehicle inat least some embodiments can free up space within the front and rearsections of the vehicle, space which can be allocated to other vehiclestructures such as the interior cavities/storage compartments discussedabove. Further, the placement of cooling system components in themid-section of a vehicle in at least some embodiments can reduce therisks of clogging/puncture of the cooling system components and/or canreduce the length of coolant lines that are utilized in those systems.Additionally, with respect to the exhaust system, the muffler whenplaced in the mid-section of a vehicle can be vertically-oriented andconfigured to resist backflow of water from the exhaust pipe back intothe engine, as well as positioned so as to reduce the possibility ofundesirable excessive heat dissipation occurring in relation to othercomponents of the vehicle.

In at least some embodiments, the present invention relates to a framefor a reduced-size vehicle having a front section, a mid-section and arear section positioned successively adjacent to one another between afront end and a rear end and having left and right sides extendingbetween the front and rear ends. The frame includes a first strutportion extending generally through the mid-section from the frontsection to the rear section, and a second strut portion extendinggenerally through the mid-section from the front section to the rearsection, where the first strut portion is positioned generally higherthan the second strut portion, and is at least indirectly coupled to thefirst strut portion. The frame further includes a third strut portionextending outward toward at least one of the left and right sidesrelative to the first strut portion, where the third strut portion iscoupled at least indirectly to at least one of the first and secondstrut portions.

Further, in at least some embodiments, the present invention relates toa frame for a reduced-size vehicle having a front section, a mid-sectionand a rear section positioned successively adjacent to one anotherbetween a front end and a rear end and having left and right sidesextending between the front and rear ends, where a central axis of thevehicle extends from the front section to the rear section. The frameincludes at least one first strut portion extending within themid-section generally parallel to the central axis, and at least onesecond strut portion extending from the at least one first strutportion, where the at least one second strut portion includes at leastone of a loop portion and a c-bracket portion extending within one ofthe front and rear sections of the vehicle. At least one of the loopportion, the c-bracket portion and a further connecting portionextending between ends of the c-bracket portion is configured to absorbenergy associated with an impact between the reduced-size vehicle and anexternal object.

Additionally, in at least some embodiments, the present inventionrelates to a frame of a reduced-size vehicle. The frame includes a firstframe portion extending underneath a saddle-type seat of the vehicle,and a second frame portion at least indirectly coupled to the firstframe portion and extending underneath a floor portion of the vehicle.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a perspective view of an exemplary reduced-size vehicle, inthis example shown to be an ATV, in accordance with at least someembodiments of the present invention;

FIG. 2 is a perspective view of an exemplary internal frame that couldbe employed in the vehicle of FIG. 1 (as viewed from a position adjacenta front right portion of the frame) in accordance with at least someembodiments of the present invention;

FIGS. 3, 4, 5 and 6 respectively are perspective (as viewed from aposition adjacent a front left portion of the frame), top plan, frontelevation and left side elevation views of an additional exemplaryinternal frame that is similar to that of FIG. 2, and which also couldbe employed in the vehicle of FIG. 1;

FIG. 7 is an additional perspective view illustrating how the exemplaryinternal frame of FIGS. 2-6 could deform in the event of a head-oncollision of the vehicle of FIG. 1 with a substantially immovable object(at least in some circumstances);

FIGS. 8( a) and 8(b) are perspective views of two alternate exemplaryinternal frames that could be employed in the vehicle of FIG. 1 inaccordance with at least some alternate embodiments of the presentinvention;

FIGS. 9( a) and 9(b) are top plan and left side elevation views of anadditional alternate exemplary internal frame that could be employed inthe vehicle of FIG. 1 (or a similar vehicle) in accordance with at leastsome alternate embodiments of the present invention;

FIGS. 10 and 13 are perspective views of exemplary internal componentsof the vehicle of FIG. 1 (as viewed from positions adjacent a frontright portion and a front left portion of the vehicle, respectively)including a slightly modified version of the exemplary internal frame ofFIGS. 3-6, front and rear internal compartments within the vehicle, andvarious components of other vehicle systems;

FIG. 11 is the same perspective view as provided in FIG. 10, exceptinsofar as certain of the suspension system components of the vehiclehave been removed and insofar as the internal compartments of thevehicle are shown both when installed and when removed from the vehicle;

FIGS. 12, 14 and 15 respectively are top plan, front elevation and sideelevation views of the internal components shown in FIG. 10;

FIG. 16 is an exemplary cross-sectional view of internal components of avehicle taken along the front axle of the vehicle, where the internalcomponents are similar to those shown in FIGS. 11 and 14, and whereinthe internal components are shown in positions that would occur duringan operational circumstance in which the front wheels are moved upwardrelative to the frame of the vehicle;

FIG. 17( a) is a front elevation view similar to that of FIG. 14;

FIG. 17( b) is a front elevation, schematic, partially-exploded, cutawayview of a further alternate embodiment of A-arms;

FIGS. 17( c)-(d) are front elevation views similar to that of FIG. 17(a) except insofar as the suspension system of the vehicle employs aMacPherson strut arrangement in place of twin A-arms (and with storagecompartments shown in phantom), in accordance with at least someembodiments of the present invention;

FIG. 18 is a left side elevation view of the vehicle of FIG. 1 furthershowing the internal compartments of FIGS. 10-16 (in phantom) andadditional external front and rear storage compartments mounted on racksat front and rear sections of the vehicle, along with approximateindicators of centers of gravity of each of these compartments (ifempty) and the vehicle as a whole;

FIGS. 19( a)-(c) respectively are perspective views of the rack at thefront section of the vehicle of FIG. 18, the external front storagecompartment of FIG. 18 mounted on that rack, and internal compartmentbeneath that rack (as the compartment would appear if removed from theremainder of the vehicle);

FIG. 20 is a perspective view of a portion of an exemplary front sectionof body work of a vehicle such as that shown in FIG. 18, with the rackat the front section removed to reveal an interior of the front internalcompartment in accordance with at least some embodiments of the presentinvention;

FIG. 21 is a perspective view of an exemplary front internal compartmentsuch as that shown in FIGS. 10-16 and 18-20, along with an exemplaryopenable lid, on which could be mounted onto the front rack of FIGS. 19(a)-(c);

FIGS. 22( a)-(c) show side elevation views of an exemplary hingecomponent that could be used to fasten and support a lid and/or racksuch as that of FIG. 21 with respect to the underlying vehicle (e.g.,with respect to the interior of an internal compartment beneath thelid/rack);

FIG. 23 shows a perspective view of the rear internal compartment ofFIG. 18 in combination with an openable lid and the rear rack of FIG.18, where the lid/rack is supported with respect to the internalcompartment by way of alternate exemplary hinge components differingfrom that of FIGS. 22( a)-(c);

FIG. 24 shows a perspective view of an alternate exemplary embodiment ofa rear internal compartment differing from that of FIGS. 18 and 23,where the compartment includes a partly fixed top portion and a lidmounted to the top portion by way of a pair of hinge components thatdiffer from those of FIGS. 22 and 23;

FIGS. 25( a)-(f) illustrate several exemplary manners in which lids tothe internal compartments can be mounted on an ATV;

FIGS. 26( a)-(b) illustrate two exemplary seals that can be employed inconjunction with the internal compartments and lids of FIGS. 21, 23, 24and 25 allowing for those compartments to be both openable andwatertight when closed;

FIG. 27 is a schematic top plan view of an exemplary floor portion ofone of the internal compartments of FIGS. 10-16 and 18 in which thefloor portion includes a drain/drain plug allowing the compartment to bedrained;

FIGS. 28( a)-(c) respectively show an interior side cutaway portion ofthe front internal compartment of FIG. 18, a cross-sectional view of ahinge locating pocket formed along that side cutaway portion taken alongline A-A of FIG. 28( a), and an alternate cross-sectional view of athreaded insert capable of being mounted along the side cutaway portion;

FIGS. 29-31 are perspective views of various exemplary embodiments ofthe reduced-size vehicle of FIG. 1 in which the vehicles are equippedwith cooling systems at the mid-sections of the vehicles and the flow ofair through the cooling systems is largely vertical;

FIG. 32 is a left side elevation view (shown partly in cutaway) of thereduced-size vehicle of FIG. 31 that reveals exemplary internalcomponents of the cooling system when the cooling system is a forcedair-cooled cooling system;

FIGS. 33 and 34 are left side elevation views (shown partly in cutaway)of the reduced-size vehicles shown in FIGS. 31 and 29, respectively,which reveal exemplary internal components of the cooling systems of thevehicles when the cooling systems are water-cooled cooling systems;

FIGS. 35( a) and (b) respectively show top plan and left side elevationviews of some of the internal components of the reduced-size vehicle ofFIG. 33, including an internal frame (which is the same as that shown inFIG. 2), suspension system components and cooling system components, andinclude cross hatching used to indicate volume voids that are formedwhen a vertical cooling path is employed in the vehicle as shown;

FIG. 36 illustrates exemplary air flow patterns around and through thereduced-size vehicle of FIGS. 31 and 32 when the vehicle is being drivenforward by an operator;

FIG. 37 is a perspective view of an exemplary vertical muffler thatcould be implemented within the vehicle of FIG. 1 in accordance withsome embodiments of the present invention, where the view shows innercompartments of the muffler and schematically indicates gas flowpatterns within the muffler during operation;

FIG. 38 is a cross-sectional view of an exemplary muffler such as thevertical muffler of FIG. 37 where the muffler includes a plurality ofinner chambers that serve to reduce the likelihood of liquid passingthrough the muffler from the exhaust outlet and back into the engine ofthe vehicle;

FIGS. 39( a) and (c) are schematic views of two alternate embodiments ofmufflers that can be used in the vehicle of FIG. 1; and

FIGS. 39( b) and (d) are additional schematic views of the mufflersshown in FIGS. 39( a) and (c), respectively, where bottom chamberswithin the mufflers are partially filled with water.

DETAILED DESCRIPTION OF THE INVENTION

Referring to FIG. 1, a perspective view of an exemplary reduced-sizevehicle in accordance with at least some embodiments of the presentinvention, namely, an exemplary all-terrain vehicle (ATV) 10, is shown.As illustrated, the ATV 10 has an exterior appearance that is similar tothe appearances of conventional ATVs, e.g., the vehicle has four tires20 (three of which are visible), a saddle-type seat 30, motorcycle-typehandlebars 40 for steering the vehicle, and a largely box-like shape.The four tires 20 typically are balloon-type tires pressurized to up to10 psi, albeit in other embodiments the tires need not be balloon tiresor be pressurized to such degree, but rather could be other types oftires, for example, non-deflatable tires, or tires pressurized at otherlevels (or tires that included or operated in association with pumpingdevices such that the tires could be inflated or deflated to a varietyof pressures).

Also, front and rear cargo racks/storage racks 50, 60, respectively, areattached to an outer surface 90 of the vehicle 10, particularly alongupper surfaces of front and rear sections 70, 80 of the vehicle,respectively. In alternate embodiments, the cargo racks 50, 60 can beconnected directly to a frame of the vehicle as discussed below withreference to FIG. 2 et seq. As will be described in further detailbelow, in accordance with at least some embodiments of the presentinvention, large internal cavities and/or large internal storagecompartments are positioned within the vehicle 10 within the front andrear sections 70, 80 of the vehicle, underneath the cargo racks 50, 60.Further as shown, the ATV 10 has foot wells/foot rests 65 on either sideof the vehicle between the front and rear tires.

Depending upon the embodiment, the relative extents of the front andrear sections 70, 80, as well as a mid-section 75 of the vehicle betweenthe front and rear sections, can be understood in any of a variety ofmanners. In at least some embodiments, the mid-section 75 of the vehiclecan be understood to extend from the frontmost surfaces of the reartires to the rearmost surfaces of the front tires, with the frontsection 70 then being understood to extend from the rearmost surfaces ofthe front tires forward and the rear section 80 being understood toextend from the frontmost surfaces of the rear tires rearward. Also, inat least some embodiments, the mid-section 75 of the vehicle can beunderstood to be that section of the vehicle that is between the largeinternal cavities and/or storage compartments existing within the frontand rear sections of the vehicle. Further, in at least some embodiments,the front section 70 of the vehicle can be understood to be the sectionof the vehicle that is in front of the seat 30 or the handlebars 40(e.g., from a frontmost or rearmost extent of the handlebars forward),the rear section 80 of the vehicle can be understood to be the sectionof the vehicle that is behind an operator (e.g., a first personcontrolling the vehicle rather than any passenger positioned behind thatfirst person) or behind a rearmost portion of the foot wells 65, and themid-section 75 can be understood as being the section of the vehiclebetween the front and rear sections.

Additionally, in at least some embodiments, the front section 70 can beunderstood as that portion of the vehicle that is forward of the frontaxle of the vehicle, the rear section 80 can be understood as thatportion of the vehicle that is rearward of the rear axle of the vehicle,and the mid-section 75 can be understood as the portion of the vehiclein between those axles. In at least some further embodiments, themid-section can be understood as the portion of the vehicle between thefoot wells 65, under the seat 30 (or under the operator), and or betweenthe racks. In at least some additional embodiments, the front, rear andmid-sections of the vehicle can be sections that correspond toparticular portions of a frame supporting the vehicle (e.g., front, rearand middle portions of frames that are discussed in more detail below).In still additional embodiments, the extents of the front, rear andmid-sections can be understood in still additional manners, includingmanners that involve different combinations of the above-discussedconsiderations (for example, the mid-section 75 could also be understoodas extending from just in front of the handlebars to the frontmostsurfaces of the rear tires or to the rear axle).

While FIG. 1 shows the ATV 10, the present invention is intended to beapplicable to a wide variety of different types of reduced-size vehiclesincluding not only ATVs, but also various types of utility vehicles(UVs) and other similar vehicles (e.g., in-airport personneltransporters and the like) that are intended to provide mobility, rapidspeed (e.g., greater than 14.4 miles per hour), and/or carryingcapacity, and/or towing capacity for people and/or items/materials. Atthe same time, reduced-size vehicles as discussed herein are notintended to encompass machines that perform specific specializedfunctions upon the environment over which they are traversing such as,for example, operator-ridable lawn mowers or snow-blowers, bulldozers,excavators or forklifts (albeit the present invention is intended toencompass reduced-size vehicles that tow trailers that potentially havecapabilities of these types), nor are reduced-size vehicles intended toencompass small, plastic-framed, electric-powered children's toys orlow-speed (e.g., less than 14.4 miles per hour) golf carts. To theextent that the present invention relates in particular to ATVs, theterm ATV as used herein can encompass any of a variety of vehicles thatfit into conventional definitions of ATVs as are known in the art, forexample, vehicles that generally have a 48 inch width or less. Utilityvehicles can include, for example, commercial utility vehicles andrecreational utility vehicles. The present invention is applicable tovehicles having four wheels (e.g., two front wheels and two rear wheels)and also other wheel arrangements. For example, the present invention isalso applicable to reduced-size vehicles having six wheels (e.g., twowheels in front, and four wheels in back).

Depending upon the embodiment, the present invention is intended toencompass reduced-size vehicles of any of these types (e.g., not merelyATVs such as the ATV 10), where the vehicles include any one or more ofthe features described in detail above and below. The present inventionis also intended to encompass variations and/or combinations of thefeatures described below as would be evident to those having ordinaryskill in the art.

Reduced-Size Vehicle Having Improved Frame Design

Referring to FIG. 2, an exemplary embodiment of a frame 100 that can beimplemented into reduced-size vehicles such as the ATV 10 of FIG. 1 isshown in a perspective view. Additionally, referring to FIGS. 3-6, aslightly modified version of the frame 100, shown as a frame 100′, isshown in a perspective view (FIG. 3), a top plan view (FIG. 4), a frontelevation view (FIG. 5) and a left side elevation view (FIG. 6). In theembodiments of FIGS. 2-6, the frames 100, 100′ include multiple struts(or tubes/bars/rods) 110 that are coupled to one another (e.g., boltedtogether or welded together in the case of metallic struts) or formedintegrally with one another. As is evident from a comparison of theframes 100, 100′ shown in FIGS. 2-6 and the ATV 10 shown in FIG. 1, theframes 100, 100′ generally have outer perimeters that largely conform tothe outer perimeter or “silhouette” of the vehicle, particularly alongthe vehicle's ends and sides.

With respect to each of the frames 100, 100′, the struts 110 inparticular include a pair of upper primary struts 120 that extend in adirection that is generally parallel to a central axis 125 extendingfrom a front portion 130 of the respective frame (see FIG. 2 inparticular for the central axis) toward a rear portion 140 of therespective frame. The upper primary struts 120, which run side-by-sideto one another in an approximately parallel manner, are spaced quiteclosely to one another such that the saddle-type seat 30 can be fitabout those struts, and consequently the primary struts 120 resemblecorresponding struts of a conventional motorcycle-type frame as isemployed in many conventional ATVs. However, in contrast to conventionalframe designs, the upper primary struts 120 do not extend the fulllength (or close to the full length) of the ATV 10 but rather extendonly about half of the length of the vehicle (or less), within a middleportion 135 of the frame. The front and rear ends 150 and 160,respectively, of the upper primary struts 120 are connected to front andrear loop struts 170 and 180, respectively, of the respective frames100, 100′. As discussed in greater detail below, these loop struts 170,180 help to define large interior cavities or spaces within which can besituated large internal compartments or chambers (see FIG. 10).

Also included within each of the frames 100, 100′ are a pair of lowerprimary struts 190. The lower primary struts 190 extend generally alonga bottom portion of the respective frames 100, 100′, in a manner that islargely parallel to the upper primary struts 120 and to the central axis125 along much of the lengths of the struts 190. However, in contrast tothe upper primary struts 120, the lower primary struts 190 run the fulllength of the respective frames 100, 100′ through each of the frontportion 130, middle portion 135 and rear portion 140 (and substantiallythe full length of the vehicle). Proximate the ends of the respectiveframes 100, 100′, the lower primary struts 190 include upwardly directedportions 200 that slope upward and attach to end portions 205 of thefront and rear loop struts 170, 180.

In addition to the lower primary struts 190, the frames 100, 100′further each include side struts 210 that generally extend outward anddownward from the left and right sides of the front loop strut 170 andthen back inward and upward to the rear loop strut 180. In at least someembodiments, the side struts 210 are positioned under, and help todefine, footrests of the reduced-size vehicle. Auxiliary struts 220further link the side struts 210 with the lower primary struts 190,which themselves are also coupled to one another by way of the auxiliarystruts 220. Another one of the auxiliary struts 220 similarly connectsthe two upper primary struts 120 with one another. Further, as shown,the frames 100, 100′ also each include four horizontal support struts230, two of which are coupled to the lower primary struts 190 at therespective front portions 130 of the respective frames 100, 100′ and twoof which are coupled to the lower primary struts at the respective rearportions 140 of the respective frames. Further, four more verticalsupport struts 235 link the front and rear loop struts 170,180 to therespective horizontal support struts 230.

While nearly identical, the frames 100 and 100′ of FIG. 2 and FIGS. 3-6,respectively, differ in two minor respects. First, the frame 100′ ofFIGS. 3-6 includes an X-brace 213 coupling the upper primary struts 120and the horizontal support struts 230 in the rear of the vehicle. TheX-brace 213 serves to further strengthen the frame 100′ longitudinally,laterally, and vertically (e.g., in terms of the relative positioning ofthe upper primary struts 120 relative to the lower primary struts 190 towhich the rear horizontal support struts 230 are coupled). In additionto the X-brace, the frame 100′ also differs from the frame 100 insofaras each of the side struts 210 of the frame 100′ include first andsecond outward bends 214 (see in particular FIG. 4) such that the sidestruts 210 along most of their length are positioned farther from thecentral axis of the vehicle/frame than the side struts of the frame 100(due to this difference, while for simplicity the side struts andauxiliary struts are respectively labeled with numerals 210 and 220 ineach of FIGS. 2-6, it would be appropriate to label the side struts andat least some of the auxiliary struts of the frame 100′ with differentnumerals than the side struts and the corresponding auxiliary struts ofthe frame 100). Thus, while each of the frames 100, 100′ can each beemployed in the vehicle of FIG. 1, the frames 100, 100′ also could beused in slightly different vehicles having slightly different outercontours, particularly in terms of their footrests.

The particular arrangement of struts 110 of the frames 100, 100′ shownin FIGS. 2-6 can be varied depending upon the embodiment. For example,in some alternate embodiments, the lower primary struts 190 can also bea series of struts that connect various ones of the auxiliary struts 220to one another rather than long struts to which the auxiliary struts areconnected. Also for example, the side struts 210 could be long strutsthat bend upward to connect to the rear (or front) loop strut 180 but donot bend upward to connect to the front (or rear) loop strut 170, andinstead bend inward to connect to the lower primary struts 190 (e.g.,taking the place of the frontmost side struts 220 shown in FIGS. 2-6).In such case, additional auxiliary struts could be used to connect theside struts to the front (or rear) loop strut 170.

The frames 100, 100′ shown in FIGS. 2-6 are advantageous in comparisonwith the frames of conventional ATVs in a number of manners. First, asmentioned above and discussed in greater detail below, the frames 100,100′ make it possible for large internal compartments to be positionedwithin the ATV both within its front and rear sections 70 and 80,respectively, along its front and rear ends. Second, as illustrated inadditional FIG. 7, in the event of an accident in which the ATV 10impacts a substantially stationary object such as a tree or pole (e.g.,as represented by a pole 245) head-on, the front loop strut 170 bearsthe brunt of the impact and dissipates substantial amounts of the energyof the impact such that an operator situated on the ATV does notexperience as much of the force associated with the impact as might bethe case with ATVs of conventional design. That is, the front loop strut170 constitutes a deformable structure that can collapse during impact.

Further, because the front loop strut 170 extends all of the way aroundthe large internal cavity defined (at least in part) by the loop strut,the loop strut also helps to protect anything that happens to bestored/contained within any compartment situated within that cavity.Although not shown in FIG. 7, similar protective and energy dissipativebenefits are provided by the rear loop strut 180 in the event of a rearcollision and by the side struts 210 (and the auxiliary struts 220 aswell) in the case of a side impact. Additionally, it will be understoodthat while FIG. 7 shows in particular an impact being experienced by theframe 100 of FIG. 2, the above discussion is equally applicable withrespect to the frame 100′ of FIGS. 3-6.

Further, the frames 100, 100′ are also advantageous insofar as, becausethe primary struts 120 do not extend the entire length of the ATV as inmany conventional designs, the damage caused by the ATV 10 upon externalobjects with which the ATV might collide during an accident is reduced.That is, in at least some circumstances, the frames 100, 100′ do nottend to “pierce” external objects with the upper primary struts 230 inthe event of a collision, but rather merely “bump into” such externalobjects with the front or rear loop struts 170,180. Additionally,because the side struts 210 assist the primary struts 120,190 inmaintaining the relative positions of the front and rear portions130,140 of the frames 100, 100′, the frames are better able toresist/tolerate torques that are placed upon the respective framesduring impacts or during other operational stresses in which the frontportion 130 of a given frame tends to be rotated in a direction oppositeto that of the rear portion (e.g., about the axis 125) of that frame.Torques/forces are run through the foot wells of the ATV 10 along itssides (via the side struts 210) rather than merely along the saddle-typeseat 30 of the ATV and corresponding primary struts 120, 190. Theauxiliary struts 220 also assist in maintaining the relative positioningof the primary struts 120, 190 and side struts 210.

Turning to FIGS. 8( a) and 8(b), alternate embodiments of the vehicleframes 100, 100′ are shown as frames 240 and 290, respectively. Withrespect to the frame 240 shown in FIG. 8( a), that frame is similar tothe frame 100 except insofar as the end portions 205 of the front andrear loop struts 170 and 180 are missing from those loop struts, suchthat the loop struts instead become front and rear c-brackets 250 and260, respectively. Further, insofar as the end portions 205 are missing,the lower primary struts 190 of the frame 100 are replaced with lowerprimary struts 270 that, instead of extending to end portions of theloop struts, extend only to inner portions 265 of the c-brackets 250,260. That is, the primary struts 270 extend to about the same locationson the c-brackets 250, 260 as the locations at which the primary struts120 connect to those c-brackets.

Also as shown in FIG. 8( a), the c-brackets 250, 260 each have pairs ofarms 275 that extend forward and rearward, respectively, up to four endpoints 280. The endpoints 280 are locations at which shock absorbers ofthe suspension system of the ATV can attach to and support the frame240, as discussed further below. Thus, the frame 240 of FIG. 8( a)differs from the frame 100 of FIG. 2 in that the frame 240 includes end(e.g., front and rear) portions that only extend so far as is necessaryto provide coupling locations for the shock absorbers.

As for the embodiment of FIG. 8( b), the frame 290 is similar to theframe 240 insofar as it includes front and rear c-brackets 300 and 310,respectively. However, in contrast to the frame 240, the frame 290 onlyincludes a single upper primary strut 320 that links the front and rearc-brackets 300 and 310. Additionally, the lower primary struts 270 ofthe frame 240 are replaced with short struts 330 that, instead ofextending upward to the c-brackets 300 and 310, merely extend up toauxiliary struts 340, which extend sideways across the frame betweenside struts 350 (which correspond to the side struts 210). Rather thanhaving both the lower primary struts 270 and the side struts 210 both becoupled to the c-brackets as in the frame 240, only the side struts 210are coupled to the c-brackets 300 and 310.

The frames 240 and 290 of FIGS. 8( a) and 8(b), although different insome respects from the frame 100 of FIGS. 2-7 and from one another,nevertheless offer some of the same advantages as the frame 100 asdiscussed above. In particular, the c-brackets 250, 260, 300 and 310define (at least partly) large cavities within which can be situatedlarge internal compartments/containers in much the same manner as theloop struts 170,180 of the frame 100 help to define cavities withinwhich such compartments can be situated. The side struts 210 and 350 ofthe frames 240 and 290 also help to improve the robustness of theoverall frame, both in terms of counteracting torques experienced by theframe (e.g., torques that would tend to rotate the front portion of theframe in an opposite direction to that of the rear portion of the frame)and in the case of accidents involving side impacts.

Although the c-brackets 250, 260, 300 and 310 do not constitute loopstruts that extend all of the way to the ends of the ATV 10, thec-brackets can be designed to interface with additional brackets formedof plastic or other materials such that the c-brackets together with theadditional brackets from complete loops (corresponding to the front andrear loop struts 170,180) that substantially extend to the front andrear ends of the ATV and help to define the internal cavities withinwhich are provided internal compartments. These additional brackets canbe formed from sufficiently robust, resilient, plastic materials thatthe brackets provide some of the same energy dissipative and otherbenefits at the front and rear ends of the ATV as are provided by theloop struts 170, 180. Thus, for an ATV employing such additionalbrackets, the consequences of an impact with an external object upon theATV will be reduced in comparison with the consequences of the sameimpact upon a conventional ATV. Also by comparison with the frame 100,the frames 240 and 290 offer some weight reduction insofar as fewerand/or shorter metallic struts are required. Further, like the frame100, the frames 240 and 290 generally require a reduced amount ofmaterial as well as a reduced amount of assembly (e.g., a reduced amountof welding) in comparison with conventional frames, and also providemore design freedom with the frame incorporating additional featuressuch as additional fuel capacity.

Turning to FIGS. 9( a) and 9(b) an additional exemplary frame 352 thatcan be employed in reduced-size vehicles such as the vehicle 10 of FIG.1 is shown. The frame 352, as with the frames 100′ and 100″ discussedabove, is highly similar to the frame 100 of FIG. 2, albeit the frame352 differs from the frame 100 in certain respects. First, as is evidentfrom the top plan view of the frame 352 shown in FIG. 9( a), a frontloop strut 354 of the frame 350 differs from the front loop strut 170 ofthe frame 100 insofar as the front loop strut 354 is substantiallyoctagonal in shape rather than hexagonal in shape. The octagonal shapeof the loop strut 354 can help to accommodate various other vehiclecomponents (e.g., as steering components). Also as shown particularly inthe right side elevation view provided by FIG. 9( b), front loop strut354 is inclined relative to a central axis of the vehicle (e.g., an axiscorresponding to the central axis 125 of FIG. 2), sloping upward fromthe front end to the mid-section of the vehicle. Such inclination of thefront loop strut 354 can be desirable for various reasons including, forexample, to improve the aerodynamics of the vehicle.

Further as shown particularly in FIG. 9( b), upper primary struts 356not only extend between the front loop strut 354 and the rear loop strut180, but also include (or are coupled to) additionaldiagonally-extending struts 358 that extend from the front loop strut354 to the lower primary struts 190. The additional diagonally-extendingstruts 358 serve to strengthen the frame 352 both longitudinally andlaterally (e.g., to at least some extent in the same manner as theX-brace 213 discussed above with respect to FIGS. 3-6). Additionally, asshown particularly in FIG. 9( b), the frame 352 includes additionalstrut portions 359 along its sides that serve to provide further supportunder the foot wells/foot rests of the vehicle, and to accommodateexhaust outlets of the vehicle.

Although FIGS. 2 through 9 show several exemplary embodiments of framesfor reduced-size vehicles in accordance with some embodiments of thepresent invention, these embodiments are not intended to be exhaustiveof all frames that come within the scope of the present invention. Forexample, while the above-described embodiments of frames all include oneor more upper primary struts extending between looping struts and/orc-brackets, in at least some embodiments the upper primary struts can beeliminated. Further for example, in some frames intended forimplementation within UVs in which conventional bench or “captain'schair” seating is desirable (rather than saddle-type seating), the upperprimary struts can be entirely eliminated, and the structural supportprovided by such upper primary struts can be alternately achieved by wayof a roll cage or reinforcement of other frame components (e.g., thelower primary struts).

Large Internal Compartments

Turning to FIGS. 10-15, exemplary internal components 15 of the ATV 10are shown in more detail. More particularly, the internal components 15shown in FIGS. 10-15 include a slightly modified version of the frame100′ shown in FIGS. 3-6, referred to as a frame 100″, along with variousadditional components associated with other vehicle systems. The frame100″ of FIGS. 3-6 in particular differs from the frame 100′ insofar asthe frame 100″ lacks the X-brace 213 of the frame 100′. As for theadditional components, among these additional components are vehiclesuspension components, which include front and rear axles 360 and 370,respectively, as well as pairs of front and rear shock absorbers 380 and390 (only one of each is shown in FIG. 10). FIGS. 10 and 13 respectivelyprovide right and left front perspective views of the internalcomponents 15, respectively, while FIGS. 12, 14 and 15 respectivelyprovide a top plan view, a front elevation view and a left sideelevation view of the internal components, respectively. FIG. 11provides an additional right front perspective view that, while similarto that of FIG. 10, shows only some of the internal components 15 shownin FIG. 10.

As shown in FIGS. 10 and 12-15, in accordance with at least someembodiments of the present invention, the shock absorbers 380, 390 ofthe ATV are vertically-oriented (or at least substantially verticallyorientated). This is in contrast to many conventional designs of ATVs inwhich the shock absorbers are positioned in an inclined manner such thatthe shock absorbers extend downward and outward away from the pointsalong the frame to which they are attached toward outer points along theaxles (e.g., toward the wheels of the vehicle), and/or in an obliquemanner within a plane that is parallel to the central axis of thevehicle (e.g., an axis such as the axis 125 of FIG. 2). Although FIGS.10 and 12-15 show the vertically-oriented shock absorbers 380, 390, inother embodiments of the present invention, the shock absorbers can bepositioned in other manners. For example, the shock absorbers could beinclined within planes that were vertical (or substantially vertical)and parallel (or substantially parallel) to the central axis 125, suchthat the shock absorbers did not extend outward away from the framealong the axles but did extend in an inclined manner within thoseplanes. In such embodiments, the right rear and right front shockabsorbers could be positioned within/along the same substantiallyvertical, parallel plane, or within/along two different planes, and thesame is true with respect to the left rear and left front shockabsorbers.

As shown in FIG. 10, tops 385 of the shock absorbers 380,390 areattached to portions of the frame 100″ that are situated substantiallyaway from the center of the vehicle, e.g., to middle locations alongside sections 395 of the front and rear loop struts 170 and 180. Theimplementation of the shock absorbers 380, 390 in a vertical (orsubstantially vertical) manner as shown in FIG. 10 is complementary inrelation to the implementation of the front and rear loop struts170,180, since the orientation of the shock absorbers makes it possibleto attach those shock absorbers to the frame 100″ even though the sidesections 395 of the loop struts 170,180 to which the shock absorbers arecoupled are positioned outward away from the central axis 125 of theframe significantly farther than the primary struts 120,190. This isalso possibly the case in appropriate alternate embodiments, such asthose discussed above in which the shock absorbers are obliquelypositioned within planes that are substantially vertical and parallel tothe central axis 125. Although not shown, similar arrangements of shockabsorbers to these discussed in relation to the frame 100″ are alsopossible in relation to the alternate frame embodiments 100, 100′, 240and 290 discussed above (as well as to other possible frameembodiments).

The complementary arrangement of the loop struts 170, 180 and the shockabsorbers 380, 390 shown in FIG. 10 differs from, and is advantageous incomparison with, the corresponding arrangements of many conventionalATVs. Because conventional ATVs employ downwardly andoutwardly-extending shock absorbers, their shock absorbers typically areattached to their frames at locations proximate the central axes of thevehicles. Consequently, such ATVs have little unobstructed space in thefront and rear sections of the vehicles where the shock absorbers arelocated. In contrast, the present complementary arrangement of the loopstruts 170,180 and shock absorbers 380, 390 (or between the c-brackets250,260, 300 and 310 and such shock absorbers) makes it possible forlarge front and rear interior cavities/volumes/spaces 400 and 410,respectively, to be provided within the front and rear sections 70, 80of the ATV 10. The large, unobstructed interior spaces 400, 410 can beused in a variety of ways, e.g., for storage space, floatationmaterials, or accessories. Further, notwithstanding the existence of thespaces 400, 410, the shock absorbers 380, 390 can be relatively long,extending from the axles to the top of the frame 100″ (extending tolocations that are proximate the tops of the tires when the suspensionsystem is fully compressed). As a consequence, high ratios of wheelmovement to shock movement (e.g., approximately or greater thanone-to-one ratios, and even nearly 1.5 to 1 or 2 to 1 ratios) becomepossible, resulting in improved suspension travel for the ATV.

As shown in FIG. 10 and further shown in FIG. 11, in at least someembodiments, large front and rear internal containers or compartments420 and 430, respectively, are fit within the spaces 400 and 410,respectively. The compartments 420, 430 can be formed by way of large,box-like tubs that are positioned within the spaces 400, 410, with thetubs being made from plastic or other appropriate materials. Althoughlargely box-like and rectangular in cross sectional shape, the actualshapes of the compartments 420, 430 can vary depending upon theembodiment, and also can vary depending upon the particularcross-section that is taken (e.g., some cross-sections of thecompartments can be trapezoidal or hexagonal). For example, as shownparticularly in FIG. 12, the particular shapes of the compartments 420,430 as viewed from a plan view generally conform to the shapes of thefront and rear loop struts 170, 180.

Additionally as shown in FIGS. 10 and 11, certain allowances are made inthe overall shapes of the compartments 420, 430 in order to allow thosecompartments to fit within the spaces 400, 410 in view of certain othersystem components. In particular, each of the front and rearcompartments 420, 430 includes a respective pair of side cutouts orindentations 440 and 450, respectively, allowing for the shock absorbers380, 390 to coexist with the compartments when the compartments areplaced within the spaces 400,410. Additionally, the front internalcompartment 420 includes an additional cutout/indentation 460 allowingfor a steering column 470 to pass underneath the compartment toward thefront axle 360 and a further cutout 461 along its bottom creating anunobstructed area within which the steering system can operate.

FIGS. 10 and 11 are similar to one another insofar as they show theframe 100″, the internal compartments 420 and 430, and various othersystem components including engine components 480 and exhaust systemcomponents 490. However, FIG. 11 reveals that, in certain embodiments,the internal compartments 420,430 are removable with respect to theframe 100″ and other components, by showing those compartments in bothinstalled and removed states (to facilitate this illustration, the shockabsorbers 380,390 are not shown in FIG. 11). Notwithstanding theembodiment shown in FIG. 11, in alternate embodiments the compartments420,430 need not be removable. Also, FIGS. 10 and 11 illustrate that theinternal compartments 420, 430 are quite large, for example, incomparison with the length of the shock absorbers. As such, in at leastsome embodiments, the internal cavity is positioned adjacent to thefirst shock absorber and extends along more than fifty percent of thelength of the first shock absorber when fully-extended. Also, in atleast some embodiments, the internal cavity has a depth that is morethan 45% (and possibly much higher, e.g., 75% or even higher) of thedistance between the bottom and top of the frame (e.g., between theupper and lower primary struts).

FIGS. 10 and 12-15 also illustrate the physical positioning of thecompartments 420, 430 in relation to various suspension systemcomponents in addition to the shock absorbers 380, 390. Further, FIGS.14 and 17( a) in particular show the front internal compartment 420 inrelation to upper and lower A-arms 670 and 720, which respectivelycouple the wheels to the frame 100″. Referring additionally to FIG. 16,a cross-sectional view taken generally along the front axle 360 ofanother embodiment of the ATV 10 having similar suspension components tothat of FIGS. 14 and 17( a) shows more clearly how the front internalcompartment 420 is in at least some embodiments shaped to accommodatemovement of the suspension system components, particularly, upward anddownward movements of the front axle 360 as allowed by the front shockabsorbers 380 (see FIG. 10). As shown, the front axle 360 is supportedrelative to the lower primary struts 190 and the front horizontalsupport struts 230 of the frame 100″ by way of pairs of upper and lowerA-arms 670′ and 720′, respectively, which differ from the A-arms 670 and720 of FIGS. 14 and 17( a) insofar as the A-arms 670 and 720 arestraight rather than having any bends. To allow for relative movementupward of the front axle 360 and the corresponding A-arms 670′, 720′(particularly the A-arm 720′), the front internal compartment 420includes tapered bottom sides 690, which provide the desired clearance.Although not shown, in at least some embodiments, similar tapered sidescould be provided with respect to the rear internal compartment 430 aswell.

Further, again referring to FIGS. 14 and 17( a), neither the upperA-arms nor the lower A-arms in at least some embodiments need becompletely straight. Rather, as shown in those FIGS., the upper A-arms670 can be configured to generally extend diagonally downward from thecentral axis of the vehicle and then, near their midpoints, to includebends (e.g., labeled with numeral 671 in FIG. 14), so as to extendsubstantially horizontally toward the wheels (as shown, the vehicle isat its designed, or substantially designed, “ride height”). Suchconfiguration of the upper A-arms 670 further increases the spaceavailable for the internal compartments 420, 430, particularly when theA-arms are elevated as in FIG. 16. As for the lower A-arms 720, each ofthose lower A-arms can include two segments (see in particular FIG. 17(a)), a first segment 730 that extends outward away from the lowerprimary struts 190 in a substantially straight manner and then a secondsegment 740 that dips downward relative to the first segment 730. As aresult of the second segments 740 that dip downward, outer ends 750 ofthe lower A-arms 720 are somewhat lower than in the embodiment of FIG.16. As a result, the clearance of the ATV with respect to the ground isincreased.

Referring to FIG. 17( b), a further embodiment of suspension systemcomponents are shown in which the lower A-arms 720, 720′ shown in FIGS.14, 16 and 17 are replaced with modified lower A-arms 722, respectively(the upper A-arms 670 are the same as those of FIG. 14). With respect tothe modified lower A-arms 722 of FIG. 17( b), each of those modifiedlower A-arms includes three segments (in a front plane), a first segment732 that extends both upward and outward from an inner end 734 thatwould be attached to the lower primary struts (not shown), a secondsegment 736 that extends substantially horizontally outward from thefirst segment, and a third segment 738 that extends both downward andoutward from the second segment. As in the case of the A-arms 720,clearance of the ATV with respect to the ground is enhanced through theuse of the modified lower A-arms 722. It should be further noted thatFIGS. 16 and 17( b) also illustrate that the two ends of the front axle360 are coupled to, and driven by way of, a differential 700 thattransmits rotational energy to the ends of the front axle by way oflinking portions 710.

Although the above-described FIGS. show embodiments of twin A-arm typesuspension systems, the present invention also is intended to encompassembodiments that employ other types of suspension systems. For example,referring to FIGS. 17( c) and 17(d), cross-sectional views of twoalternate embodiments of suspension systems 762 and 764, respectively,are shown in which MacPherson strut-type arrangements are employed. Thesuspension system 762 of FIG. 17( c) in particular is shown to include aMacPherson strut-type suspension arrangement in which the modified lowerA-arms 720 of FIG. 17( a) (or A-arms similar thereto) are still employedto connect the wheels to the frame, but the upper A-arms are replaced byshort arms 766 that directly couple the wheels to the shock absorbers380, without any additional coupling of the wheels to the frame. Thesuspension system 764 of FIG. 17( d) in particular is shown to include aMacPherson strut-type suspension arrangement in which the modified lowerA-arms 722 of FIG. 17( b) (or A-arms similar thereto) are still employedto connect the wheels to the frame, but the upper A-arms are replaced byshort arms 768 that directly couple the wheels to the shock absorbers380, without any additional coupling of the wheels to the frame.Although FIGS. 17( c) and 17(d) show the suspension systems associatedwith the front wheels of the vehicle, similar MacPherson strut-typesuspension systems can also (or instead) be employed with respect to therear wheels of the vehicle. By employing such MacPherson strut-typesuspension systems in the front and/or rear of the vehicle, the internalcompartments 420, 430 (and cavities within which those compartments arepositioned) can be further increased in size relative to what would bepossible in embodiments employing A-arm-type suspension systems.

Turning to FIG. 18, the ATV 10 is shown to be fully loaded with multiplestorage compartments that include, in addition to the internalcompartments 420, 430 (shown in phantom), additional optional front andrear exterior storage compartments 500 and 510, respectively. Thestorage compartments 500 and 510 respectively rest upon and are attachedto the front and rear storage racks/cargo racks 50 and 60, respectively,along an upper surface 515 of the ATV 10. Given that the front and rearinternal compartments 420 and 430 have widths that approach the width ofthe overall ATV 10 (e.g., over 50% of the width of the vehicle), giventhat the front and rear exterior storage compartments 500 and 510 havewidths that are no more than the width of the ATV (and are largely thesame as those of the corresponding internal compartments), and given theoverall length and depth dimensions of the respective compartments asshown in FIG. 18, it is evident that the overall volume of space withinthe internal compartments typically is considerably larger than that ofthe exterior storage compartments. Further, given that the internalcompartments 420, 430 are quite large, the need for exterior storagecompartments (particularly exterior storage compartments that are largeand might impede operator visibility or negatively affect dynamichandling) is significantly reduced in comparison with conventional ATVs.

Also as shown in FIG. 18, in contrast to the exterior storagecompartments 500 and 510, which have centers of gravity 520 that areabove a center of gravity 530 of the entire unloaded ATV 10, theinternal compartments 420,430 have centers of gravity 540 that are atapproximately the same level as the center of gravity 530 of the vehicleunladen. Consequently, loading of the internal compartments 420,430 doesnot typically cause the overall center of gravity of the ATV 10 to beraised, in contrast to loading of the exterior storage compartments 500,510. Additionally, given that the relative dimensions and volumes of theinternal compartments 420, 430 are considerably larger than those of theexterior storage compartments 500, 510 as discussed above, it wouldrarely be the case that the loading of all of the various compartmentsof the ATV 10 would substantially raise the overall center of gravity ofthe ATV, particularly assuming that the internal compartments 420, 430are loaded first before any loading (or even attachment) of the exteriorstorage compartments 500, 510. Indeed, in many cases the loading of theinternal compartments 420, 430 tends to lower the overall center ofgravity of the ATV (e.g., when only the lower portions of the internalcompartments are filled), and thus tends to expand the vehicle'soperating envelope and increase the vehicle's tip-over and rolloverangles, which enhance stability and safety. Additionally, since theoverall center of gravity 530 of the overall vehicle will beconsiderably higher than that shown when an operator (and/or passenger)are riding on the vehicle, the internal compartments (particularly whenfilled) serve to significantly reduce the actual center of gravity ofthe vehicle under operating circumstances. This all is in contrast toconventional ATVs, in which all or nearly all of the storage capacity ofthe ATVs occurs by way of external storage.

Referring to FIGS. 19( a)-(c), additional perspective views of theexemplary front storage rack (or carrier) 50, front internal compartment420 and front exterior storage compartment 500 of FIG. 18 are provided.FIG. 19( a) in particular shows simply the rack 50, while FIG. 19( b)shows the rack along with the front internal compartment 420 below itand FIG. 19( c) shows the rack along with the front exterior storagecompartment 500 above it. Referring additionally to FIG. 20, aperspective top view of a front portion 550 of the ATV 10, which largelybut not entirely corresponds to the front section 70 of FIG. 1, is shownin cutaway from the remainder of the vehicle. More particularly, FIG. 20shows the front portion 550 with each of the front storage rack 50 and alid or cover for the front internal compartment 420 (as described below)removed, to reveal the interior of the front internal compartment 420.

The front and rear internal compartments 420, 430 can take a variety offorms and serve a variety of purposes depending upon the embodiment. Insome embodiments, the internal compartments 420, 430 are used (orusable) primarily for storing and/or carrying loads that an operator (orother party) wishes to move from one location to another location viathe ATV or other reduced-size vehicle having the compartments. Also, asdescribed further below, in at least some embodiments, the compartments420, 430 are optionally sealable (or even permanently sealed) so as toprovide air tight and/or watertight compartments that can be used tocarry fluids, used to carry equipment that should not be exposed to theoutside environment (e.g., electronic equipment that should not beexposed to rainwater), or used to increase the displacement and therebythe buoyancy of the ATV or other reduced-size vehicle. In someembodiments, one or both of the compartments 420, 430 also can beemployed as coolers (or thermoses) to store various items that requireheating or refrigeration such as, for example, food or drink. In somesuch embodiments, Styrofoam liner(s) or other appropriate thermalinsulation components can be provided within one or both of thecompartments to provide appropriate insulation. Further, depending uponthe embodiment, the liners or other appropriate thermal insulationcomponents can be integrally formed with the compartments, or formed asseparate components and then inserted into the compartments (e.g., suchthat the liners would generally follow the contours of the compartments,along the insides of the compartments).

In at least some embodiments (as shown, for example, in FIG. 11), theinternal compartments 420, 430 are geometrically configured to enhancetheir usefulness as large storage containers. More particularly, in suchembodiments, the internal compartments 420, 430 have cross-sections thatare substantially convex polygons (e.g., all interior angles are 90degrees or greater), with the possible exception of theallowances/indentations described above (e.g., the indentations 440,450, 460, 461, etc.), and/or are designed so that lines connectinglargely or substantially all pairs of points on opposing interiorsurfaces within the compartments would not cross or be obstructed by anyintermediary surface of the compartments. That is, the internalcompartments 420, 430 are configured so as to create the largestpossible uninterrupted or unobstructed volumes within the compartments.As a result, the internal compartments 420, 430 in many embodiments willbe capable of holding large-volume items such as, for example, 5 gallonwater containers or 5 gallon gas containers.

While it is typically desirable that the size (e.g., the largeness) ofthe internal compartments 420, 430 be maximized for a given vehicle, theactual size of the internal compartments can be evaluated in a number ofmanners. To begin with, the size of the compartments can be evaluatedsimply based upon the actual volumes within the compartments, e.g., thenumber of gallons of fluid that the compartments could hold. While asimple volume measure is one useful figure of merit, particularly interms of determining whether a given compartment is capable of providingsufficient fluid-carrying capacity or sufficient displacement, otherfigures of merit also are of interest, particularly depending upon theparticular application(s) in which it is envisioned that a given ATV orother reduced-size vehicle might be used. For example, in view of theabove discussion concerning the desirability of having internalcompartments with “convex polygon” cross-sectional shapes, other usefulfigures of merit can include the largest-diameter sphere orlargest-width cube that will fit within a given compartment. In somecases, it is of interest whether particularly objects or devices willfit into a given internal compartment. In at least some embodiments ofthe invention, each of the front and rear internal compartments can holdspheres that are more than 10″ in diameter, up to 16″ in diameter oreven larger (particularly if the lids of the compartments and/or theracks were bulbous in shape). Also, in at least some embodiments of theinvention, each of the front and rear internal compartments can hold acube that is more than 10″ by 10″ by 10″ in volume, up to 12″ by 12″ by12″ in volume, or even 16″ by 16″ by 16″ in volume or even larger.

Further, the length, width, depth/height or other cross-sectionaldimensions of the internal compartments 420, 430, or areas or volumescalculated by multiplying two or more of these dimensions, can also beof interest as figures of merit, either by themselves or in relation toother dimensions of the overall vehicle such as the width of thevehicle, the height of the vehicle, and/or the length or wheelbase ofthe vehicle. Indeed, such measurements or ratios can be of use incomparing the storage capacity of two or more comparable ATVs or otherreduced-size vehicles. The dimensions of the internal compartments thatare used in any given size evaluation can be maximum dimensions, averagedimensions, mean dimensions, or some other type of dimensions orarbitrarily-measured dimensions across the compartments.

In at least some embodiments of the present invention, such as thatshown in FIG. 11, one useful figure of merit is the ratio of the sum ofthe maximum lengths of the two (front and rear) internal compartments(where length is measured parallel to the central axis of the vehicle,e.g., the axis 125 of FIG. 2) to the wheelbase of the vehicle. Withrespect to many embodiments of the present invention, including theembodiment described with respect to FIGS. 10-15, this ratio is 65% orgreater (and, in any event, well over 50%), and in some embodiments thisratio could potentially reach as high as around 90%. Other usefulfigures of merit include, for example, the ratio of the length of aninternal compartment to the total length of the vehicle, the ratio ofthe width of an internal compartment to the total width of the vehicle,and the ratio of the depth of an internal compartment to the totalheight of the vehicle. In at least some embodiments, these respectivelength, width and depth/height ratios can attain values of between 20%and 32%, between 46% and 51%, and between 62% and 63% (where height ofthe vehicle can be measured from the ground to the top of one of theracks, or both of the racks, when the vehicle is unladen), respectively.

In certain embodiments, the internal compartments 420, 430 can be openedand closed by way of a hinged door or other openable/closeable port. Inat least some embodiments, the compartments 420, 430 include a lid ortop or cover that can be opened and closed. For example, as shown inFIG. 21, the front internal compartment 420 in some embodiments operatesin conjunction with (or can be considered as including) a lid/top 560that is coupled to the compartment by way of one or more coupling links,which can take the form of one or more hinge components 570. Each of thehinge components 570 can have a variety of forms, one of which is shownin more detail in FIGS. 22( a)-(c) in fully-closed, partly-closed, andfully-opened positions, respectively. Although not shown, in at leastsome embodiments, the lid/top 560 is configured to support a storagerack such as the storage rack 50. In such embodiments, lifting of thestorage rack 50 results in raising of the lid/top 560 so as to open thecompartment 420.

FIG. 23 further shows the rear internal compartment 430 in combinationwith a lid/top 580 (the lid/top can also be considered to be a part ofthe rear internal compartment). The lid/top 580 is coupled to the rearinternal compartment 430 by way of two hinge components 590. FIG. 23also shows that, in some embodiments, the rear storage rack 60 iscoupled directly to the top 580 such that lifting of the rack 60 resultsin the opening of the compartment 430. Further, the top 580 can have astrengthening rib 515 enabling the top to become a structural membercapable of bearing significant loads. FIG. 24 additionally shows analternate embodiment of the rear internal compartment 430, in this casereferred to as a rear internal compartment 431, where the compartmentincludes a partly fixed top portion 600 and also is coupled to anopenable top portion or lid 610, which is coupled to the top portion 600by way of hinges 620 (the lid 610 can also be considered to be part ofthe internal compartment 431).

Although FIGS. 21, 23 and 24 show the lids 560, 580, 610 as each beinghinged so as to open upward and toward the front of the ATV 10,regardless of whether the lids are for the front or rear internalcompartments 420, 430/431, the present invention is intended toencompass a variety of different configurations of lids. Referring toFIGS. 25( a)-(f), six additional exemplary lid configurations areillustrated. FIG. 25( a) in particular shows an ATV having front andrear lids 561 and 581 that each are hinged with respect to the vehicleand swing upward and outward toward the front and rear rends of thevehicle, respectively (e.g., both of the lids swing away from theoperator). FIG. 25( b) shows an alternative ATV having front and rearlids 562 and 582 that each are hinged with respect to the vehicle so asto swing upward and inward toward the mid-section of the vehicle, wherethe operator would be seated. Although not shown in FIGS. 25( a)-(f), asdiscussed above, it also is be possible for both the front and rear lidsto be hinged so as to swing toward the front (or rear) of the vehicle.

Further, it also is possible in some embodiments to have both front andrear lids 563 and 583, respectively, swing toward the left side of thevehicle as shown in FIG. 25( c), or to have both front and rear lids 564and 584, respectively, swing toward the right side of the vehicle asshown in FIG. 25( d). Additionally, as shown in FIG. 25( e), it also ispossible in some embodiments to have one of the front and rear lids,e.g., a front lid 565, swing toward the right side of the vehicle whilethe other of the lids, e.g., a rear lid 585, swing toward the left sideof the vehicle. A reverse orientation to that of FIG. 25( e) is alsopossible, as shown in FIG. 25( f) (with each of FIGS. 25( e) and (f)again providing front elevation views of vehicles). Indeed, it will beevident from FIGS. 25( a)-(f) that at least 16 different hinged lidcombinations are possible in terms of the different hinge orientationsthat can be employed with respect to the front and rear lids.

Although FIGS. 25( a)-(f) envision ATVs or other reduced-size vehiclesthat have both a front internal compartment and a rear internalcompartment that are each accessible from the top by way of a hingedlid, the present invention is also intended to encompass ATVs or otherreduced-size vehicles that have only a single large internal compartment(e.g., at either the front or the rear) and/or one or more compartmentsthat are accessible from locations other than (or in addition to) theirtops. Further, the present invention is intended to encompass vehicleshaving one or more compartments having lids that are removable but nothinged. For example, in some alternate embodiments, the lids can be slidlaterally/horizontally across the tops of the compartments along slotsformed within the interior sides of the compartments. Also, for example,the lids can be pulled off or completely removable in some other manner.Indeed, the embodiments shown and discussed above are only intended tobe exemplary, and are not intended to be an exhaustive description ofall possible arrangements of lids/tops/covers/doors or other ports inrelation to one or more internal compartments of an ATV or otherreduced-size vehicle.

Also, while FIGS. 21-24 show a number of hinge-type components that canbe utilized to couple lids or similar door-type components to internalcompartments, the present invention is intended to encompass a varietyof other hinge-type components other than those shown, which areintended to be merely exemplary. Further, the present invention is alsointended to encompass a variety of other embodiments of internal andexternal compartments and racks even though they are not shown in theFIGS. For example, one or more of the internal compartments can befurther compartmentalized into several distinct regions orsubcompartments. Also for example, the various compartments, includingpossibly various subcompartments within those compartments, can be usedfor many different specialized purposes (e.g., as one or more coolers,as one or more tool holders, for the purpose of storing/conveyinghunting equipment, and for a variety of other purposes).

In at least some embodiments, the front and rear internal compartments420, 430 in combination with their complimentary lids (or tops, covers,doors, etc.) are sealed or sealable such that the compartments arecapable of serving as buoyant compartments within the ATV 10 or servingother purposes for which it is desirable to have sealed (e.g.,watertight and/or airtight) compartments (e.g., to hold liquids). Insome such embodiments, the compartments 420, 430 each have a volume ofmore than 10 gallons, for example, 15 gallons or 17 gallons, and in atleast some embodiments, the compartments each have an even larger volumeapproaching 20 to 25 gallons per compartment (or possibly even more). Insuch embodiments, when combined with the buoyancy afforded by theremainder of the vehicle (including, in this case, four balloon tires 20and a fuel tank of the ATV 10), the overall buoyancy of the ATV issignificantly improved over conventional ATVs. Indeed, the 50 gallons ormore of displacement afforded by such compartments, in combination withthe above-estimated 72 gallons of displacement afforded by the tires 20and fuel tank and the remainder of the ATV, achieves an overalldisplacement of 122 gallons, well over the 114 gallons of displacementthat (as discussed above) would be required to keep a conventional ATVafloat when supporting an operator of average size (e.g., an operator ofabout 200 lbs). Indeed, with such displacement, it would be possible notonly to support an operator of that size but also be possible to supportup to approximately another 67 lbs of additional weight and still float.Further, because both the front and rear internal compartments 420,430are capable of providing approximately equivalent levels of buoyancy,the ATV 10 remains largely horizontal (e.g., less than 5 degrees of tiltoff of the horizontal) if the ATV enters a body of water rather thansuffering from significant tilting (e.g., having one end of the ATVbecome significantly higher than the other end of the ATV).

In certain embodiments, the internal compartments 420, 430 are fullysealed and cannot be opened. However, more commonly, the compartments420, 430 have openable lids, tops, covers, doors or other openableports, for example, as shown in FIGS. 21-24 (e.g., the lids/tops 610,580 and 560). To allow for such openable lids or other ports and at thesame time achieve satisfactory sealing of the internal compartments, itis typically desirable (although not necessary) for the lids or otherports associated with the compartments 420, 430 and the compartmentsthemselves to include one or more seals such that, when the lids orother ports are closed with respect to the compartments, liquid or gascannot enter into or exit from the compartments. FIG. 26( a) shows oneexemplary rubber seal 635 existing between the lid 610 and the storagecompartment 431 of FIG. 24, while FIG. 26( b) shows an alternateexemplary outer seal arrangement. Further, while not appropriate in allembodiments, to the extent that liquids or water can enter thecompartments 420, 430, the compartments can also include one or moredrain holes such as a drain hole 630 shown in FIG. 27 along their bottomsurfaces. The drain holes can be both unplugged to allow drainage ofliquids/water from the compartments 420, 430 as well as plugged to allowfor the compartments to be fully-sealed.

Referring further to FIGS. 28( a)-(c), in certain embodiments, the innersurfaces of the internal compartments 420,430 can include variousfeatures that allow for the attachment of the coupling links/hingecomponents such as the hinge components 570, 590 shown in FIGS. 21-23.For example, as shown in FIGS. 28( a) and (b), an inner side surface 640of the front internal compartment 420 can include a slot 650 into whicha bottom portion of one of the hinge components 570 rests.Alternatively, as shown in FIG. 28( c), a threaded insert 660 can beemployed, allowing a threaded shaft of a hinge component to be screwedinto a complementary threaded hole within the sidewall of the internalcompartment (or allowing a hinge component with a threaded hole to bescrewed onto a threaded shaft protruding from the sidewall). The use ofsuch threaded inserts can enable the cost effective manufacture of theinternal compartments in a manner similar to existing body manufacturewith injection molding, for example.

Mid-Section Cooling and Exhaust Systems

Referring to FIG. 29, the ATV 10 is shown in one embodiment to includeside air inlets 760 (only one of which is shown, the other being on theopposite side of the vehicle) that are situated on opposite sides of theoperator seat 30. As indicated by first and second arrows 770 and 780,which respectively represent air inflow into and air outflow from theATV 10, the ATV differs from conventional ATVs insofar as the coolingsystem of the vehicle for cooling the engine and related components issituated exclusively within a mid-section 790 of the ATV thatcorresponds generally to the middle portion 135 of the frame 100discussed above.

Turning to FIGS. 30 and 31, in two alternate embodiments of the ATV 10,shown respectively as ATVs 785 and 800, air inlets 765 and 810 arerespectively located at positions that are higher up and somewhatforward of the positions occupied by the air inlets 760, proximate thehandlebars 40. More specifically, the air inlet(s) 765 of the ATV 785are positioned just behind where the handlebars 40 are mounted to thevehicle (along the center of the vehicle), while the air inlet(s) 810are positioned nearly adjacent to, and to the sides of, where thehandlebars are mounted to the vehicle. Consequently, FIGS. 30 and 31respectively include arrows 775 and 820 representing the air inflow intothe air inlets 765 and 810, which respectively are moved upward andforward relative to the arrow 770 of FIG. 29, albeit the arrow 780 canstill be used to represent air outflow from underneath the vehicle ineach case. As in the case of the ATV 10 of FIG. 29, the entire coolingsystems of the vehicles in FIGS. 30 and 31 are positioned withinrespective mid-sections 795 and 830 of the vehicles 785 and 800,respectively.

The positioning of the cooling systems of FIGS. 29-31 within themid-sections 790, 795, 830 of the ATVs 10, 785, 800 is advantageous inseveral regards relative to conventional ATVs. In particular, becausethe cooling systems in these embodiments are located within themid-sections of the vehicles, and because of the locations of the airinlets 760, 765, 810, there is reduced likelihood that mud, water,seeds, grass, leaves or other undesirable materials will be receivedinto the cooling systems. Further, there is little likelihood ofpuncture or other damage to cooling system components, since the outerbodies of the ATVs 10, 785, 800 naturally create protective perimetersaround the cooling system components.

Referring to FIGS. 32-34, components of two different types of coolingsystems that can be employed within the ATVs 10, 785 and 800 of FIGS.29-31 (as well as other ATVs and reduced-size vehicles) are shown inmore detail. With respect to FIG. 32, components of a first, forcedair-cooled cooling system 840 are shown in partial cutaway. As shown,the arrangement of components of the cooling system 840 of FIG. 32 isparticularly applicable to the embodiment of ATV 800 shown in FIG. 31;however, similar arrangements could also be used with respect to theATVs 10, 785 of FIGS. 29-30 and with other ATVs and reduced-sizevehicles. The cooling system 840 of FIG. 32 in particular includes theair inlets 810 (only one is shown) and also includes a fan 850, aspinning mechanical air filter 860 located slightly above the fan, andan air discharge outlet 870 located proximate the underside of the ATV800. Air entering by way of the air inlet 810 is sucked into the ATV 800by way of the fan 850 through the air filter 860, passes by and coolsthe engine components 480, particularly finned cylinders and cylinderheads 880 on the engine, and then proceeds down and out through the airdischarge outlet area 870.

FIG. 33 shows, in partial cutaway, components of an alternate, liquidcooled cooling system 890 as implemented in another version of the ATV800 of FIG. 31, referred to as ATV 800 a. As shown, the cooling system890 includes, in addition to the air inlets 810 and the air dischargeoutlet 870 (which can be the same as that shown in FIG. 32), an electriccooling fan 900 and a radiator 910, which is connected to enginecomponents 905 by way of coolant lines 920. In this embodiment, theradiator 910 is oriented so that its large outer sides through which airflows are substantially horizontally-oriented. In contrast toconventional ATVs employing liquid cooled cooling systems, the coolantlines 920 in the present embodiment are short since the cooling system890 is within the mid-section of the ATV 800 a in close proximity to theengine components 905. Further, FIG. 34 shows, in partial cutaway,components of another embodiment of liquid cooled cooling system 885 asimplemented in the ATV 10 of FIG. 29, with the cooling system includingthe air inlets 760 (one of which is shown) rather than the air inlets810, a radiator 911 positioned adjacent the air inlets, and coolantlines 921 between the radiator and engine components 915. In thisembodiment, the large outer sides of the radiator 911 through which airflows are oriented in a substantially vertical manner and also aresubstantially parallel to a central axis of the vehicle (e.g.,corresponding to the central axis 125 of FIG. 2).

FIGS. 35( a)-(b) additionally show a number of the components of thecooling system 890 of FIG. 33 mounted on the ATV 800 a. In contrast tothe depiction in FIG. 33, FIGS. 35( a)-(b) show the ATV 800 a with mostexternal components (e.g., the outer housing or body of the vehicle)removed to reveal in more detail the components of the cooling system890 (aside from the air inlets 810 and air discharge outlet 870) alongwith the engine components 905 of the vehicle, both from a top view(FIG. 35( a)) and from a left side elevation view (FIG. 35( b)). FIGS.35( a)-(b) in particular demonstrate the compactness of the arrangementthat is achieved by virtue of providing the cooling system 890 withinthe mid-section 790 of the ATV 800 a proximate the engine components905. Again, while the arrangements of components shown in FIGS. 32-35are particularly applicable to the embodiments of ATVs 10, 800/800 ashown in FIGS. 29 and 31, similar arrangements could also be used withrespect to the ATV 785 of FIG. 30 and with other ATVs and reduced-sizevehicles.

Turning to FIG. 36, exemplary air flow patterns around and through theATV 800 of FIGS. 31-32 (or other ATVs such as the ATVs 10, 785) duringoperation are shown. As illustrated, when the ATV 800 moves forward,high velocity air 930 flows around and past the vehicle in a largelyhorizontal manner. Typically, some of the high velocity air 930 isslowed down and becomes low velocity air 940, particularly as the highvelocity air encounters the operator himself or herself. That is, someof the high velocity air 930 is blocked, and as a result eddy currentsand other swirling patterns of the low velocity air 940 are created,particularly around the mid-section 830 of the ATV 800. It is primarilythis low velocity air 940 that enters the air inlets 810 (or air inlets760 or 765). After the low velocity air 940 enters the air inlets 810,and passes through the cooling system 840 (or 885 or 890), the airleaves the vehicle by way of the air discharge outlet 870 and thenpasses underneath the vehicle as expelled cooling air 950.

The air flow patterns created by the ATV 800 and its cooling systemcomponents during operation are advantageous in several regards. Whenthe ATV 800 is moving forward, the operator creates a low velocity, highpressure zone over the air inlets 810, while high velocity airproceeding underneath the vehicle creates a low pressure area below thevehicle. Consequently, air has a natural tendency to move through thecooling system 840 from the low velocity, high pressure region above thevehicle to the high velocity, low pressure area beneath the vehicle.Further, insofar as the air passing through the particular coolingsystem embodiments shown in FIGS. 32-34 is, in each case, driven by afan that in turn is driven by the engine, the engine will not overheatduring idling, and hot air will not chimney upward out of the airinlet(s) toward the operator so long as the engine continues to run.

In the present embodiment, the expelled cooling air 950 is expelled in adirection away from the operator and does not tend to heat the operator.However, in alternate embodiments, one or more vents could be providedproximate the saddle-type seat 30 (e.g., near the operator's legs) thatwould allow some or all of the expelled cooling air 950 to pass by theoperator and thus provide heating to the operator, or to be passedthrough and around the seat. In further alternate embodiments, suchvents would be provided, but could be switched on and off (e.g., openedor closed) by the operator, thus giving the operator control overwhether heated air was provided proximate the operator or directed awayfrom the operator (or some combination of both).

In accordance with at least some embodiments of the present invention,some or all of the exhaust system components 490 are also located withinthe mid-section 790 of the ATV 10 (or other ATV or reduced-sizevehicle). In particular, as is evident from a comparison of FIGS. 1 and10, a muffler 955 can be provided within the mid-section of the ATV 10,for example, under the saddle-type seat 30 of the ATV. As discussedfurther below, in addition to the muffler 955, the exhaust systemcomponents 490 typically further include an exhaust inlet, an exhaustoutlet, a cooling air inlet and a cooling air outlet.

Referring additionally to FIG. 37, in a preferred embodiment, themuffler 955 includes a substantially cylindrical housing 960 that isorientated so that its central axis 965 is vertically-oriented (or atleast substantially or largely vertically oriented) within the ATV 10.The housing 960 can be top mounted to the frame 100 or other vehiclecomponent by a single rubber mount. Within the cylindrical housing 960are a first, interior cylindrical chamber 970 and also a second, annularchamber 975 existing between the housing 960 and the interiorcylindrical chamber 970. Cooling air is provided from the cooling system(e.g., from a fan such as the cooling fan 900 discussed above or anauxiliary fan) to a cooling air inlet 980 that is coupled to (or formedintegrally with) the muffler 955, where the cooling air inlet is locatedproximate a top 962 of the muffler 955/cylindrical housing 960 and is incommunication with the annular chamber 975. Upon entering the air inlet980, the cooling air proceeds into the annular chamber 975 and thenswirls around that chamber in a generally downward manner until it exitsthe chamber at a cooling air outlet 985 along a bottom 990 of themuffler 955.

The bottom 990 of the muffler 955 further is coupled to (or formedintegrally with) both an exhaust inlet 995 and an exhaust outlet 999,which are both in communication with the interior cylindrical chamber970 of the muffler. Exhaust from the engine is communicated by way ofthe exhaust inlet 995 into the interior cylindrical chamber 970, whereit is cooled due to the cooling air flow within the annular chamber 975.The cooled exhaust then exits the muffler 955 by way of the exhaustoutlet 999, which can transport the exhaust to a variety of locationsaround the vehicle for emission. To the extent that the exhaust outlet999 is longer than in most conventional ATVs (e.g., to the extent thatexhaust is communicated form the mid-section 790 of the ATV 10 to therear end of the ATV), the length of the exhaust outlet helps toattenuate noise from the engine.

Positioning of the exhaust system components 490, particularly themuffler 955, within the mid-section 790 of the ATV 10 is advantageousrelative to positioning of those components elsewhere such as in therear section of the vehicle. In particular, because the muffler 955 is afairly large component, the placement of the muffler within themid-section 790 of the ATV 10 makes space available within othersections of the vehicle at which the muffler might otherwise be located,particularly within the rear section. Such space can then be used forother purposes, for example, the implementation of internal compartmentssuch as the rear internal compartment 430 discussed above. Further,placement of the muffler within the mid-section 790 of the ATV 10actually allows for the use of a larger muffler than in conventionalembodiments of ATVs in which the muffler is placed in the rear of thevehicle, since the muffler's size is not constrained by the need to workaround the other components in the rear of the vehicle (e.g., suspensioncomponents).

Appropriate placement of the muffler 955 and other exhaust systemcomponents, particularly the exhaust outlet 999, can also reduce orpreclude backflow of water or other liquids through the muffler and intothe engine. Additionally, in some embodiments the muffler 955 caninclude features that further reduce the chances of backflow. Forexample, as shown in FIG. 38, in one such embodiment an interiorcylindrical chamber 971 of the muffler (e.g., taking the place of thechamber 970 described above) is further divided into multipleinterconnected interior chambers 1000 connected by vertical stand tubesthat together function as a water labyrinth tending to preclude waterfrom making its way back from the exhaust outlet 999 into the exhaustinlet 995 and subsequently into the engine.

In the embodiment shown, there are four such interior chambers 1000shown as chambers 1001, 1002, 1003, and 1004, each of which is at alevel higher than the previous chamber. As shown, the exhaust outlet 999is linked to the third highest chamber 1003. The third highest chamber1003 in turn is coupled by way of an interior vertical stand tube 1005to the second highest chamber 1002. That second highest chamber 1002 inturn is coupled to the highest chamber 1004 by an additional interiorvertical stand tube 1006. Further, the highest interior chamber 1004 isthen coupled to the lowest chamber 1001 by way of a further interiorvertical stand tube 1007, with the interior chamber 1001 then beingcoupled to the exhaust inlet 995. As shown, preferably, the verticalstand tubes 1005 and 1007 are coupled to the respective interiorchambers 1003 and 1004 at relatively high points within those chambers,while the exhaust outlet 999 and vertical stand tube 1006 are coupled tothose respective interior chambers at lower points within thosechambers. Consequently, if water enters the exhaust outlet 999, thewater fills up the interior chamber 1003 nearly completely before waterthen proceeds into the chamber 1002, and likewise water fills up theinterior chamber 1004 nearly completely before the water proceeds intothe chamber 1001 and then into the exhaust inlet 995.

Referring now to FIGS. 39( a), 39(b), 39(c) and 39(d), two alternateembodiments of mufflers 1010 and 1040 are shown, respectively. Moreparticularly, FIG. 39( a) shows the muffler 1010 to have lower, middleand upper chambers 1012, 1014 and 1016, respectively. The chambers 1012,1014 and 1016 are situated within an exterior housing 1034 of themuffler 1010, and an annular cavity 1036 exists between the exteriorhousing 1034 and outer surfaces 1038 of the chambers 1012, 1014 and1016. Cooling air enters the exterior housing 1034 by way of an entrance1040 and passes through the annular cavity 1036 and then out a bottom1042 of the muffler, such that the exterior housing 1034 is cooledrelative to the exhaust within the chamber 1012, 1014, and 1016. Furtheras shown, the upper chamber 1016 is coupled to an exhaust inlet 1018 ofthe muffler, while the lower chamber 1012 is coupled to an exhaustoutlet 1020 of the muffler. Additionally, the upper chamber 1016 iscoupled to the lower chamber 1012 by way of a first intermediate channel1022. A second intermediate channel 1023 links the upper chamber 1016 tothe middle chamber 1014, with an upper lip 1024 of the channel 1023being positioned somewhat higher than an upper lip 1026 of the firstintermediate channel 1022, and substantially lower than an upper lip1028 of the exhaust inlet 1018 within the upper chamber 1016. At abottom 1030 of the first intermediate channel 1022 is located anopenable/closable door or valve 1032 that is coupled to the bottom byway of a hinge 1033.

As shown by a comparison of FIGS. 39( a) and 39(b), the muffler 1010operates so as to allow exhaust to pass through the muffler and at thesame time to restrict any water (or other fluid) backflow from theexhaust outlet 1020 back to the exhaust inlet 1018. The valve 1032 asshown in FIG. 39( a) is normally in an open position so as to allow forthe passage of exhaust out of the muffler 1010. However, as shown inFIG. 39( b), in circumstances where a substantial amount of water 1044backflows into the lower chamber 1012 by way of the exhaust outlet 1020,the valve 1032 closes (at least temporarily) to prevent backflow of thewater into the upper chamber 1016. To achieve this operation, the valve1032 typically is made from a material that tends to float when situatedwithin water. When exhaust pressure within the muffler becomessufficient, the valve 1032 still will open to allow egress of theexhaust notwithstanding the floatation of the valve.

In addition to preventing water backflow through operation of the valve1032, the muffler 1010 also prevents backflow due to the arrangement ofchannels 1022 and 1023. If water should fill up the lower chamber 1012and the channel 1022 so as to rise above the upper lip 1026 of thechannel 1022 and begin to fill the upper chamber 1016, the water willonly rise above the upper lip 1028 of the exhaust inlet 1018 and beginto spill into that inlet after the water has first risen above the upperlip 1024 of the channel 1023, completely filled up the middle chamber1014, and then further nearly completely filled up the upper chamber1016.

Referring further to FIGS. 39( c) and 39(d), the muffler 1050 isidentical to the muffler 1010 except insofar as a spring-loaded checkvalve 1048 is employed in place of the hinged door valve 1032. As shownin FIG. 39( c), the valve 1048 is normally open with a check ball 1045hanging from the channel 1022 by way of a spring 1046. However, as shownin FIG. 39( d), the valve 1048 closes when the level 1044 of water risessufficiently. As with the hinged door valve 1032, the ball 1045 istypically made of a material that floats within water so that the valve1048 closes when water sufficiently fills the lower chamber 1012.

As shown in FIGS. 39( a)-(d), proper operation of the mufflers 1010,1050 presumes that the muffler 1010 is substantially verticallyorientated, e.g., where the upper chamber is physically above the lowerchamber, etc. It should be noted that, in these and similar embodimentsemploying labyrinths such as the muffler of FIG. 38 (and even in manyembodiments that do not employ labyrinths, such as the muffler of FIG.37), the mufflers tend to have a longer dimension (e.g., an axial lengthof a cylinder) and a shorter dimension (e.g., a diameter of thecylinder). In such embodiments, vertical orientation of the muffler alsocorresponds to aligning the longer dimension of the mufflersubstantially parallel to a vertical axis (e.g., normal to the ground).

The implementation of cooling system components and exhaust systemcomponents within the mid-section of an ATV as described above providesnumerous advantages. Placement of the cooling system components in themid-section enhances the cooling of the engine by improving the flowcharacteristics of the cooling system, better protecting criticalcomponents, and effectively venting heated discharge air. Further, itcentralizes the necessary cooling apparatus in the vehicle, thuscreating a more compact cooling solution, and further simplifiespowertrain packaging, so as to free up valuable space within the vehicleallowing for alternative uses of that space. In particular when appliedto ATVs, this arrangement creates a vehicle that is safer to use, due toenhanced mobility and mass centralization, and is more comfortable tooperate because hot discharge air is effectively directed away from theoperator (and/or any passenger) or, in alternate embodiments, moreeffectively directed toward the operator (and/or any passenger).Further, the ATV is more reliable to operate because critical powertraincomponents are out of harms way and less easily damaged due toencounters with environmental hazards.

Further, in particular with respect to the exhaust system components,the above-described embodiments improve performance by allowing the useof a larger volume muffler, reducing backpressure (which in part is dueto the larger volume of the muffler) and lowering the output noise levelresulting in quieter operation and increased power. Further, because ofthe larger muffler volume, there is a higher muffler volume to enginevolume ratio, making tuning and noise targets easier to optimize andbalance. Additionally, because the muffler uses forced cooling air, theair flow directed around the external surface of the muffler cools thehottest area first, and the top-down flow of cooling air enables heat tobe forced out the bottom of the muffler to provide even cooling and toreduce the potential for excessive heating of the muffler, particularlyits exterior surface, and components located nearby to the muffler.Because the muffler cooling air outlet is moved downward and is facingthe ground, it also is more comfortable to work behind the ATV, and themuffler is quieter during operation.

The arrangement of the exhaust system components further enables thevehicle to ford deeper water crossings as the muffler can be designed(e.g., in accordance with FIG. 38) so that water does not back flow intothe engine when the outlet is under water. The vertical orientation ofthe muffler allows other components of the vehicle to be packaged closeby, particularly when the vertical muffler is cooled by forcing airunder a heat shield and over the muffler, and also allows for easierinstallation. This cooling feature will become increasingly valuable asemission control apparatuses such as catalysts (which further heat theexhaust) begin to be used and eventually become necessary. Theapplication of one or more of these features therefore results in ATVsthat are one or more of more powerful, quieter, less prone to wateringestion, and more durable, with enhanced comfort for the operator andadditional packaging flexibility for the vehicle designer. The endresult is an ATV with superior handling, safety, comfort, convenience,and reliability.

It is specifically intended that the present invention not be limited tothe embodiments and illustrations contained herein, but rather that theinvention further include modified forms of those embodiments includingportions of those embodiments and other embodiments and combinations ofelements of such various embodiments as come within the scope of thefollowing claims.

1. A frame for a reduced-size vehicle having a front section, amid-section and a rear section positioned successively adjacent to oneanother between a front end and a rear end, and left and right sidesextending between the front and rear ends, the frame comprising: a firststrut portion extending generally through the mid-section from the frontsection to the rear section; a second strut portion extending generallythrough the mid-section from the front section to the rear section,wherein the first strut portion is positioned generally higher than thesecond strut portion, and the second strut portion is at leastindirectly coupled to the first strut portion; and a third strut portionextending outward toward at least one of the left and right sidesrelative to the first strut portion, wherein the third strut portion iscoupled at least indirectly to at least one of the first and secondstrut portions, and forms a loop that is situated substantially withinthe front section, wherein the frame is configured for receiving asteering column and the loop is configured to extend substantiallybetween a steering column receiving position and the front end.
 2. Theframe of claim 1, wherein the third strut portion at least partiallydefines an internal cavity substantially within the front section. 3.The frame of claim 1, wherein the third strut portion extends outwardbeyond a side surface of a seat of the vehicle.
 4. The frame of claim 1,wherein the first strut portion at least partly extends within a seat ofthe vehicle.
 5. The frame of claim 1, wherein a fourth strut portionextends generally underneath a foot rest of the vehicle.
 6. The frame ofclaim 1, further comprising a fourth strut portion that couples at leasttwo of the first, second and third strut portions together.
 7. The frameof claim 6, further comprising a fifth strut portion extending generallythrough the mid-section from the front section to the rear section,wherein the fifth strut portion extends alongside at least one of thefirst and second strut portions.
 8. The frame of claim 1, wherein theframe further comprises a fourth strut portion and a fifth strutportion, wherein the fifth strut portion is a loop portion, and whereinthe fourth strut portion couples the third and fifth strut portions. 9.The frame of claim 1, wherein the third strut portion is configured toabsorb energy during an impact between the reduced-size vehicle and anexternal object.
 10. A reduced-size vehicle comprising the frame ofclaim 1, wherein the reduced-size vehicle is one of an all-terrainvehicle (ATV) and a utility vehicle (UV).
 11. The reduced-size vehicleof claim 10, further comprising an internal compartment positionedwithin an internal cavity defined at least in part by the third strutportion, wherein the internal compartment extends at least 45% of adistance between the first and second strut portions.
 12. A frame for areduced-size vehicle having a front section, a mid-section and a rearsection positioned successively adjacent to one another between a frontend and a rear end, and the frame having left and right sides extendingbetween the front and rear ends, wherein a central axis of the vehicleextends from the front section to the rear section, the framecomprising: at least one first strut portion extending within themid-section generally parallel to the central axis; and at least onesecond strut portion extending from the at least one first strutportion, wherein the at least one second strut portion includes asubstantially closed loop portion extending within the front section ofthe vehicle, and wherein the loop portion is situated substantially in ahorizontal plane, and wherein the loop portion is configured to absorbenergy associated with an impact between the reduced-size vehicle and anexternal object; and at least one third strut portion extending from theat least one first strut portion, wherein the at least one third strutportion includes a loop portion extending within the rear section of thevehicle.
 13. The frame of claim 12, further comprising at least onefourth strut portion extending within the mid-section, wherein thefourth strut portion is at least partly positioned outward toward one ofthe left and right sides beyond a surface of a seat of the vehicle. 14.The frame of claim 13, wherein the fourth strut portion is within a footrest portion of the vehicle.
 15. The frame of claim 12, wherein the atleast one second strut portion at least partially surrounds a storagecompartment, and wherein the storage compartment further is configuredto absorb energy during the impact between the vehicle and the externalobject.
 16. A frame for a reduced-size vehicle having a front section, amid-section and a rear section positioned successively adjacent to oneanother between a front end and a rear end, and left and right sidesextending between the front and rear ends, the frame comprising: a firststrut portion extending generally through the mid-section from the frontsection to the rear section; a second strut portion extending generallythrough the mid-section from the front section to the rear section,wherein the first strut portion is positioned generally higher than thesecond strut portion, and the second strut portion is at leastindirectly coupled to the first strut portion; a third strut portionextending outward toward at least one of the left and right sidesrelative to the first strut portion, wherein the third strut portion iscoupled at least indirectly to at least one of the first and secondstrut portions, and forms a loop that is situated substantially withinthe front section; and a fourth strut portion that extends outwardtoward at least one of the left and right sides relative to the firststrut portion, wherein the fourth strut portion is coupled to the firstand second strut portions and forms a loop in the rear section that issubstantially situated in a horizontal plane.
 17. The frame of claim 16,wherein the third strut portion at least partially surrounds a storagecompartment, and wherein the storage compartment further is configuredto absorb energy during an impact between the vehicle and the externalobject.
 18. A frame for a reduced-size vehicle, the vehicle including afront section, a mid-section and a rear section positioned successivelyadjacent to one another between a front end and a rear end and left andright sides extending between the front and rear ends, the framecomprising: a first strut portion extending generally between the frontsection and the rear section; a second strut portion extending generallythrough the mid-section from the front section to the rear section,wherein the first strut portion is positioned generally higher than thesecond strut portion, and the second strut portion is at leastindirectly coupled to the first strut portion, and wherein the first andsecond strut portions extend through the mid-section of the vehicle; athird strut portion coupled at least indirectly to each of the first andsecond strut portions and forming a closed loop that is situatedsubstantially within the front section wherein the loop is situated in asubstantially horizontal plane; and a fourth strut portion coupled atleast indirectly to each of the first and second strut portions andforming a closed loop that is situated substantially within the rearsection wherein the loop is situated in a substantially horizontalplane.
 19. The frame of claim 18, wherein the second strut portion incombination with the first strut portion tends to counteract a torqueacting about an axis that is substantially parallel to a central axis ofthe vehicle and that is applied to a front end of the frame in relationto the rear end of the frame.
 20. A frame for a reduced-size vehiclehaving a front section, a mid-section and a rear section positionedsuccessively adjacent to one another between a front end and a rear end,and left and right sides extending between the front and rear ends, theframe comprising: a first strut portion extending generally through themid-section from the front section to the rear section; a second strutportion extending generally through the mid-section from the frontsection to the rear section, wherein the first strut portion ispositioned generally higher than the second strut portion, and thesecond strut portion is at least indirectly coupled to the first strutportion; a third strut portion extending outward toward at least one ofthe left and right sides relative to the first strut portion, whereinthe third strut portion is coupled at least indirectly to at least oneof the first and second strut portions, and forms a loop that issituated substantially within the front section; and fourth and fifthstrut portions extending generally through the mid-section from thefront section to the rear section, wherein the fourth strut portionextends outward toward the right side relative to the first strutportion, and the fifth strut portion extends outwards toward the leftside relative to the first strut portion.